ACS Publications. Most Trusted. Most Cited. Most Read
My Activity
CONTENT TYPES

Simple Synthesis of Large Graphene Oxide Sheets via Electrochemical Method Coupled with Oxidation Process

Cite this: ACS Omega 2018, 3, 8, 10233–10242
Publication Date (Web):August 30, 2018
https://doi.org/10.1021/acsomega.8b01283

Copyright © 2018 American Chemical Society. This publication is licensed under these Terms of Use.

  • Open Access

Article Views

7059

Altmetric

-

Citations

LEARN ABOUT THESE METRICS
PDF (7 MB)
Supporting Info (1)»

Abstract

In this paper, we report a simple two-step approach for the synthesis of large graphene oxide (GO) sheets with lateral dimensions of ≈10 μm or greater. The first step is a pretreatment step involving electrochemical exfoliation of graphite electrode to produce graphene in a mixture of H2SO4 and H3PO4. The second step is the oxidation step, where oxidation of exfoliated graphene sheets was performed using KMnO4 as the oxidizing agent. The oxidation was carried out for different times ranging from 1 to 12 h at ∼60 °C. Prepared GO batches were characterized using a number of spectroscopy and microscopy techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV–visible spectroscopy. Raman and thermogravimetric analysis techniques were used to study the degree of oxidation in the as-synthesized GO batches. The UV–visible absorption spectrum showed an intense peak at 230 nm and an adjacent band at 300 nm corresponding to π–π* and n−π* transitions in all samples. Normalized FTIR plots were used to calculate the relative percentages of oxygen-containing functional groups, which were found to be maximum in GO (6 h). Boehm titration was used to quantify the functional groups present on the GO surface. Overall GO sheets obtained after 6 h of oxidation, GO (6 h), were found to be the best. XRD pattern of GO (6 h) revealed a characteristic peak at 2θ = 8.88°, with the corresponding interplanar spacing between the layers being 0.995 nm, which is among the best with respect to the previous methods reported in the literature. Raman spectroscopy showed that the degree of defect (ID/IG) area ratio for GO (6 h) was 1.24, which is higher than that obtained for GO (1.18) prepared by widely used Marcano’s approach.

Introduction

ARTICLE SECTIONS
Jump To

Graphene is an emerging two-dimensional carbon material containing sp2 hybridized carbon atoms arranged in hexagonal array. (1−4) It is a future material due to its excellent physicochemical properties such as high surface area (2630 m2 g–1), thermal conductivity (5000 W m–1 K–1), Young’s modulus (1 TPa), electron mobility (2.5 × 105 cm2 V–1 s–1), relatively high electrical conductivity at room temperature (of the order of 106), and chemical durability. (5−10) Due to its extraordinary structure-related properties, it has found potential applications in various fields of science and engineering, including biotechnology, energy, and environment. (11−14) Some of the commonly used methods for the preparation of graphene include scotch tape method, chemical vapor deposition, liquid-phase exfoliation, electrochemical exfoliation, and chemical reduction of graphene oxide (GO). Among them, chemical reduction of GO to yield graphene sheets is the most widely used technique due to its cost-effectiveness and feasibility of processing. In this process, graphite is first oxidized to give GO nanosheets using Hummers’ method and then reduced to yield graphene. During oxidation, C═C double bonds break down and oxygen functional groups, such as −COOH, −OH, and C–O–C, are introduced in the basal plane and at the edges of the graphene sheets. These functional groups are further reduced by chemical, thermal, and electrochemical treatments.
The well-known Hummers’ method was introduced by Hummers and Offman in 1958, which made use of sodium nitrate (NaNO3) and potassium permanganate (KMnO4) in H2SO4 for performing oxidation of graphite flakes. Generation of toxic gases, residual nitrate content, and low yield are some of the major flaws of the Hummers’ process. (15−23) Later, several modifications have been proposed in the Hummers’ process to synthesize GO sheets with high degree of oxidation. (20,22,24) In 2010, Marcano and co-workers replaced NaNO3 with H3PO4. They concluded that GO prepared using KMnO4, H2SO4, and H3PO4 exhibit higher degree of oxidation compared to that synthesized using KMnO4, H2SO4, and NaNO3. Also, they reported that this, often called improved Hummers’ method, does not produce any toxic gases and is suitable for large-scale production of GO.
Recently, some more methods have been reported for synthesizing GO, which include elimination of NaNO3 from reaction mixture or using K2FeO4 instead of KMnO4 or using K2FeO4 + KMnO4. A consolidated list of various techniques reported for the GO synthesis is given in Table 1. In the past, the electrochemical exfoliation of graphite has been performed to obtain graphene using different types of electrolyte solutions, such as organic/inorganic salts or solvents, bases, strong acids, oxidants, polymers, ionic liquids (sodium tungstate) aqueous solution, tetrasodium pyrophosphate, potassium sulfate, NaOH, sulfuric acid (H2SO4), phosphoric acid (H3PO4), HNO3, HCl, HBr, cetyl trimethylammonium bromide, and protic ionic liquid. (25−34)
Table 1. Comparative Analysis of GO Synthesis Methods Reported in the Literature
reaction timereaction temperature (°C)carbon sourceoxidizing agentsGO synthesis methodID/IG ratiointerlayer spacing “d” (nm)ref
  graphiteN2HO5, KClO3    (32)
  graphiteN2HO5, KClO3    (33)
1.5 h>35powder graphite flakeNaNO3, H2SO4, KMnO4Hummers’   (15)
12 h>50graphite flakeH2SO4/H3PO4, KMnO4improved Hummers’ 0.95 (20)
13 h>35graphite powderH2SO4, NaNO3, KMnO4, K3Fe(CN)6modified Hummers’ 0.77 (23)
7.5 days40graphite powderNaNO3, H2SO4, KMnO4Hummers’ and improved Hummers’ with purification 0.81 (16)
7.5 days40graphite powderH2SO4, KMnO4improved Hummers’ with purification0.610.831 (17)
580graphite powderK2S2O8, MnO2, P2O5, and H2SO4improved synthesis   (19)
2450graphite powderH2SO4, H3PO4, and KMnO4    (21)
535graphite flakeKMnO4, K2FeO4, H3BO3 GO1-1.07GO1-0.83 (34)
GO2-0.94GO2-0.81
655–60graphite electrodeH2SO4, H3PO4, KMnO4electrochemical followed by oxidation with KMnO40.940.996present work
Most of the studies in the literature use GO synthesized by Marcano’s approach using graphite powder as the precursor. The motivation for the present work was to synthesize graphene oxide sheets using graphite electrode as precursor material. The purpose of using electrochemical approach is to exfoliate or to peel off graphite layers from electrode into the reaction mixture and further oxidize the material to synthesize GO sheets. Most of the previously reported synthesis methodologies require longer time, which increases the production cost. This is due to the fact that the slow diffusion of oxidants between the graphene sheets restricts the formation of GO. (20) Present study also aims to minimize the time required for synthesizing GO. It may be noted that the electrochemical approach is easily scalable as well.
In the present study, we report the synthesis of GO from graphite electrode. First, graphite was exfoliated from graphite electrode in acidic mixture (H2SO4 + H3PO4), which caused exfoliation of graphene layer and increased the interlayer spacing between the sheets. In the second step, the exfoliated graphene sheets were oxidized using KMnO4. The obtained GO sheets were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–visible and Raman spectroscopy. The morphological characteristics of the sheets was analyzed by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) techniques.

Results and Discussion

ARTICLE SECTIONS
Jump To

Structure and Microstructure Studies

The XRD patterns of graphite electrode and exfoliated graphite are shown in Figure 1a. Pristine graphite exhibits it characteristic diffraction peak at 2θ = 27.6° for the (002) plane, with an interlayer d-spacing of 0.323 nm determined using Bragg’s law equation
(1)
where n = 1 and θ is the Bragg’s angle. In case of exfoliated graphite, diffraction peak for the (002) plane was observed at 2θ = 26.4° for which the interlayer d-spacing was determined as 0.337 nm. After exfoliation of graphene sheets from graphite electrode, an insignificant change in d-spacing was observed. This indicates that only pure graphene sheets are peeled off from electrode without any chemical modification (i.e., oxidation) into the electrolyte solution. The XRD patterns of different batches of GO are shown in Figure 1b. Results revealed that with increasing reaction times, the (002) peak shifts toward lower 2θ value, suggesting an increase in the interlayer d-spacing. The d-spacing observed for GO (12 h) was determined as 1.046 nm, which is 1.18 times greater than that of GO synthesized using Marcano’s approach. Also, the diffraction peak observed for different GO batches is broader compared to that of precursor material graphite, suggesting deterioration in the crystallinity of the material (Figure 1b). Therefore, it can be concluded that well-separated GO sheets were obtained using our two-step method. (16,17,20,23,35,36)

Figure 1

Figure 1. XRD patterns of (a) graphite electrode and exfoliated graphite and (b) different GO batches.

Raman spectroscopy is a powerful tool for characterizing graphene and its derivatives. Raman spectra of different GO batches are shown in Figure S1 (Supporting Information). Defect-free graphite exhibits characteristic G-band at 1579 cm–1 in Raman spectroscopy, which corresponds to E2g vibration mode of sp2 hybridized carbon atoms. Upon oxidation from graphite to GO, rupturing of C═C double bond occurs, which results in the generation of sp3 hybridized carbon. (37−39) The presence of sp3 hybridized carbon atoms in GO is reflected by a defect band at 1357 cm–1, which is also known as D-band. (40) The ratio of the area of D-band to G-band, i.e., ID/IG, gives the measure of the disorderness/defects in GO. (41) The area ratios ID/IG for different GO batches are shown in Figure 2. It should be noteworthy here that with an increase in the oxidation time, ID/IG ratio increases significantly up the oxidation time of 6 h and then decreases. The highest value of the ID/IG ratio of 1.24 was achieved for the GO batch corresponding to 6 h. A further increase in oxidation time resulted in the lowering of ID/IG ratio. The reason for this may be the structural dominance of graphene sheets over the disordered areas, which causes lowering of the intensity of D-band. (42−45) For GO batch prepared using Marcano’s approach, the ID/IG ratio was determined as 1.18, which is lower compared to the ID/IG ratio for the GO (6 h) batch.

Figure 2

Figure 2. Calculated crystallite sizes from Raman and XRD data, and the ID/IG area ratio for GO samples with varying oxidation times and Marcano’s method.

Raman spectroscopy was further used to determine the crystallite size of the as-synthesized GO sheet. The formula used for calculating the crystallite size is given below (41−43)
(2)
where La is the crystallite size and λ is the wavelength of laser source (514 nm). The crystallite size obtained for different GO batches are shown in Figure 2. The crystallite size for GO (1 h) batch was determined as 20.9 nm, which reduced to 13.5 nm when reaction was performed for 6 h. This decrease in crystallite size is attributed to the decrease in the GO domains due to the oxidation-induced structural disorder in the form of sp3 hybridized carbon atoms. Also, increase in oxidation time beyond 6 h caused an increase in the crystallite size. The crystallite size of GO prepared using Marcano’s approach is greater than that of GO (6 h) batch, suggesting that more defect levels were induced using our approach compared to Marcano’s approach. The crystallite size of the as-prepared sheets was also determined using the Debye–Scherrer equation (D = 0.94λ/(β cos θ), where λ is the X-ray wavelength (0.15404 nm), β is the full width at half-maximum, and θ is the diffraction angle). The crystallite sizes from XRD data of different GO batches (Figure 2) were found be in the range of 3.3–4.3 nm. It is seen that there is difference in crystallite size range as calculated from XRD and Raman spectra. This is due to the fact that crystallite size calculated from Raman spectra depends on the excitation wavelength. Raman spectra obtained from lower excitation wavelength is likely to give crystallite size similar to that obtained from XRD data. (43)

Chemical and Molecular Study

The FTIR spectra of pristine graphite are shown in Figure 3a, which consist of low-intensity peaks at 3434 and 1630 cm–1 for O–H and C═C stretching vibrations modes, respectively. The presence of various functional groups in different GO batches is observed in the FTIR spectra (Figure 3a). Different batches of GO sheets reveal a peak at 3434 cm–1, which is attributed to the O–H stretching vibration modes of −COOH and C–OH functional groups. Further, all of the GO batches show peaks at 1747 and 1637 cm–1, which are attributed to C═O stretching and C═C bending vibration modes. For other functional groups like C–O–H and C–O–C, peaks appeared at 1403, 1235, and 1045 cm–1. (20,23,46−48)

Figure 3

Figure 3. (a) FTIR plots for GO batches; (b, c) normalized FTIR plot; and (d) RPOCFG profile for GO samples with varying oxidation times and Marcano’s method (M).

A more detailed study of the structures of the as-prepared GO batches was obtained by plotting normalized FTIR plots (according to the procedure reported by Guerrero-Contreras and Caballero-Briones), (43) which are shown in Figure 3b,c. The normalized FTIR data of various GO batches revealed prominent peaks at 1724, 1622, 1407, 1226, and 1044 cm–1 for C═O stretch in carboxylic, C═C aromatic stretch, C–O–C ether, C–OH stretch in acids, and C–O–C epoxy groups, respectively. The intensity of various peaks increased with an increase in reaction time and attains maxima for GO (6 h). The intensity of peaks for oxygen-containing functional groups was found to decrease at higher reaction times (>6 h). It should be noteworthy here that the intensities of various peaks in GO prepared by Marcano’s approach are significantly lower compared to those of GO (6 h), suggesting higher concentration of oxygen-containing functional groups in GO (6 h). The deconvoluted FTIR spectra for the range of 1500–1850 cm–1 for all GO batches is given in Supporting Information Figure S2. The deconvoluted spectrum of GO (1 h) showed a single peak for aromatic C═C stretch at 1622 cm–1. However, a new peak was observed at 1580 cm–1 for batches corresponding to 2 h or more, which is again assigned to C═C stretching vibrational mode of substituted aromatic rings in GO. It was also observed that the intensity of this peak increased with time, indicating an increase in the concentration of substituted aromatic ring in the samples. This increase is due to introduction of various functional group in the graphene network. The maximum intensity of this peak was achieved for the GO (6 h) batch, suggesting the presence of higher concentration of functional group compared to other batches.
The degree of oxidation of different GO batches was further evaluated by calculating the relative percentage of oxygen-containing functional groups (RPOCFG) with respect to the presence of all functional groups observed in the wavenumber range of 900–1850 cm–1 (for all peaks in Figure 3b,c). RPOCFG was calculated using the following formula (43)
(3)
Figure 3d presents the value of RPOCFG in different GO batches. It was observed that the value of RPOCFG increased with an increase in the time of oxidation. The highest value of RPOCFG of 68.1% was achieved for GO (6 h) batch, which reflects the highest concentration of oxygen-containing functional groups in the sample. For other GO samples, the RPOCFG values were lower. This indicates that the lower oxidation degree was achieved for these batches. Also, GO prepared using Marcano’s approach gave RPOCFG < 68.1%.
XPS analysis, shown in Figure 4, further reveals the chemical composition and binding states of carbon and oxygen in GO (6 h). The XPS images of GO (6 h) are mainly composed of C 1s and O 1s. Figure 4a shows the deconvoluted spectra of C 1s, in which three characteristic peaks are fitted at 284.38, 286.69, and 288.54 eV for C–C/C═C bond (sp2 and sp3 structure), C–OH/C–OC bond, and O═C–OH groups, respectively. (49)Figure 4b shows the deconvoluted spectra of O 1s, which also shows the presence of three characteristics peaks at 531.44, 532.81, and 533.74 eV corresponding to C═O, C–OH, and adsorbed water molecules. (50,51) The XPS images of the GO (6 h) batch revealed peaks corresponding to C 1s and O 1s only, suggesting the absence of any other impurity in the prepared sample. Further, the degree of oxidation achieved was explain in terms of O/C ratio, which is determined as 0.531.

Figure 4

Figure 4. (a) XPS (a) C 1s and (b) O 1s spectra of GO (6 h).

Boehm titration is a qualitative as well as quantitative tool for the determination of various oxygen-containing functional groups, such as carboxylic acid, phenols, and lactones. This method is based on the difference in the acidities of the above-mentioned functional groups. The concentration of various types of acidic functional groups is calculated under the assumptions that NaHCO3 neutralizes carboxylic groups, Na2CO3 neutralizes carboxylic acid and lactone, and NaOH neutralizes all carboxylic, lactonic, and phenolic groups. The results of Boehm titration are shown in Figure 5. It is observed that the concentration of phenolic group is maximum in the GO (1 h) batch and minimum in the GO (6 h) batch. On the other hand, the concentration of carboxylic and lactonic groups increases in a regular manner with an increase in reaction time. This increase in carboxylic groups is attributed to the oxidation of some of the hydroxyl groups to carbonyl groups and then to carboxylic groups during the course of oxidation reaction. Similarly, increase in lactonic functional groups is due to the loss of water molecules from the adjacent carboxylic and phenol groups (at the edge of GO sheets). The proposed oxidation mechanism corroborates well with the available literature. (12,52)

Figure 5

Figure 5. Concentrations of various functional groups in GO samples with varying oxidation times and Marcano’s method.

UV–Visible Studies

The structural modification of graphite by increasing the degree of oxidation so as to convert it into GO is also evident from the UV–visible spectra shown in Figure 6. Dispersions of different GO batches were prepared in deionized water by ultrasonication and their absorption spectra were recorded. It was observed that all GO batches revealed a sharp absorption peak at ≈230 nm, which corresponds to the electronic excitation form π → π* molecular orbital of the aromatic sp2 domains, i.e., C═C bonds. In addition, a weak shoulder band was also observed at ≈300 nm, which was associated with the n → π* electronic transitions due to various oxygen-containing functional groups, such as −COOH, −CHO, and C–O–C. The increase in the intensity at 300 nm is attributed to the presence of highly oxidized graphene basal plane. This produces a greater amount of isolated aromatic rings (or lesser amount of extended conjugated aromatic rings) in the prepared GO batches, which in turn increases the intensity of C═C bonding peak at ≈230 nm. (50,53,54) Similar results were also reported in the literature. (16,42,55)

Figure 6

Figure 6. UV–visible spectra of different GO batches.

Morphological Studies

The morphologies of different GO batches were analyzed by FE-SEM, and the results are presented in Figure 7a–g. The SEM images of the GO sheets corresponding to 1 and 2 h (Figure 7a,b) reveal the formation of poorly exfoliated wrinkled structures. It may be noted that the lateral dimensions of sheets are of the order of 10 μm or greater and fit the definition of large GO sheets. (56) From energy-dispersive X-ray (EDX) measurement, the C/O ratios for the GO (1 h), GO (2 h), and GO (4 h) batches were determined as 1.13, 1.15, and 1.17, respectively. On the other hand, GO (6 h), GO (8 h), GO (10 h), and GO (12 h) showed the formation of well-exfoliated sheet-like morphology with curled edges. The C/O ratios for these batches were found to be 0.94, 1.14, 1.21, and 1.28, respectively. The TEM images of GO (6 h) at two different magnifications (Figure 7h,i) also reveal the formation of a thin sheet. The crystallinity of GO sheets was also investigated by the selected area electron diffraction (SAED) technique (Figure 7j), which showed the presence of diffused concentric diffraction rings indicating low crystallinity of the material. (4,20,23) This observation is well corroborated with the result of XRD. Hence, it can be concluded that the oxidation of graphite to graphene oxide is accompanied with the worsening of the crystalline property of the material. The semi-amorphous nature of GO has been reported by a number of investigators. (57,58)

Figure 7

Figure 7. FE-SEM images of GO corresponding to reaction times of (a) GO (1 h), (b) GO (2 h), (c) GO (4 h), (d) GO (6 h), (e) GO (8 h), (f) GO (10 h), and (g) GO (12 h); (h, i) TEM images of GO (6 h); and (j) SAED pattern of GO (6 h).

Thermogravimetric Studies

Thermogravimetric analysis (TGA) technique was further used as a tool to analyze the degree of oxidation and thermal stability of the as-synthesized GO batches. TG curves of different GO batches are shown in Figure 8. GO batches obtained for various reaction times revealed ca. 17–23% weight loss in the temperature range of 25–150 °C due to the removal of physically adsorbed and intercalated water molecules from the sheets. At 150 °C, sudden weight loss was observed for different GO batches, which could be due to the removal of labile oxygen-containing functional groups, such as epoxy, hydroxyl, carboxylate, anhydride, or lactone, from the surface of GO sheets. This indicates the presence of a large number of oxygen-containing functional groups at the edges and in the basal plane of graphene layers. This matches well with the FTIR and Boehm studies, which showed the presence of a high amount of carboxylic and lactonic groups in the GO samples obtained after oxidation for 6 h or longer. Moreover, EDX studies showed higher C/O ratio in these GO samples with oxidation time of 6 h or longer. Also, weight loss at 150 °C is more for the GO (6 h), GO (8 h), GO (10 h), and GO (12 h) batches compared to the GO (1 h), GO (2 h), and GO (4 h) batches. This indicates that with an increase in oxidation time, more oxygen-containing functional groups get introduced in the graphene skeleton, which makes GO thermally less stable. Weight loss in the range of 40–500 °C is attributed to the removal of more stable oxygen groups such as phenol and carbonyl. At temperatures >500 °C, weight loss is due to pyrolysis of GO. Overall, findings of TGA match well with those of FTIR and EDX studies, revealing high concentration of oxygen-bearing functional groups, which are responsible for the low thermal stability of the prepared GO samples. (16,20,23,59)

Figure 8

Figure 8. TG profiles of different GO batches.

Reaction Mechanism

The schematic representation of the method of GO synthesis using our two-step approach is shown in Figure 9. Briefly, graphite layers got exfoliated from the graphite electrode during the electrochemical step and formed graphite intercalated compound upon insertion of ionic species, such as HSO4, SO42–, and H+ ions, from H2SO4. In the second step, KMnO4 was added to the reaction mixture, which formed highly reactive dimanganese heptoxide (Mn2O7) species upon reaction with H2SO4. (60,61) Mn2O7 oxidized the defective sites over aromatic double bonds present in graphene skeleton. The reaction of defect centers with Mn2O7 introduced functional groups, which upon hydration with water yield −OH groups. During the course of reaction, loss of water molecule from two −OH groups occurs to from epoxy linkages. Further, sulfonic acid (−RSO3) groups are attached to the edges of the graphene structure, which upon hydration get converted into carboxylic groups. (60)

Figure 9

Figure 9. Graphical representation of the synthesis of graphene oxide using electrochemical exfoliation coupled with oxidation.

Conclusions

ARTICLE SECTIONS
Jump To

Graphene oxide sheets were successfully synthesized through a very simple electrochemical exfoliation of graphite followed by oxidation with KMnO4. The sheets were further characterized using different spectroscopy and microscopy techniques. It was found from XRD, Raman, and FTIR studies that the maximum degree of oxidation was achieved for the GO (6 h) batch. The interlayer spacing between the graphene sheets in GO (6 h) was determined as 0.995 nm with an ID/IG ratio of 1.24. The relative percentage of oxygen-containing functional groups in GO (6 h) as calculated from normalized FTIR plots was found to be the highest (68.1%). XPS and Boehm titration methods were further used to determine the binding states and concentration of various oxygen-containing functional groups in GO batches. UV–visible spectra of different batches of GO revealed a sharp intensity peak at ∼230 nm and a weak adjacent band at ∼300 nm. A detailed characterization of various GO batches reveal the formation of highly exfoliated and oxidized GO sheets with wrinkled surface and curled edges after 6 h of oxidation.

Materials and Methods

ARTICLE SECTIONS
Jump To

Materials

Graphite electrodes with dimensions of 10 cm × 1.5 cm × 0.5 cm were obtained from Graphite India Limited, Delhi. Graphite flakes with a mesh size of ∼20 μm were obtained from Sigma-Aldrich, India. Sulfuric acid (H2SO4, 98%), hydrochloric acid (HCl), diethyl ether (C4H10O), and hydrogen peroxide (H2O2, 30%) were procured from HiMedia India Pvt. Ltd. Potassium permanganate (KMnO4), orthophosphoric acid (H3PO4), and ethanol (C2H5OH) were procured from Merck, India. All reagents were of analytical grade and used without purification.

Synthesis of GO Sheets

Synthesis of GO from graphite electrode was done in two steps: (i) exfoliation of graphene from graphite electrodes so as to peel off/scratch the graphene sheets from graphite electrode with the help of applied current and (ii) oxidation of graphene into GO. In the first step, two graphite electrodes (separated by a distance of 1.5 cm) were employed as anode and cathode. They were dipped in a 66 mL mixture of H2SO4 and H3PO4 with a volume ratio of 9:1. A static current of 1.00 ± 0.1 A, optimized separately, was passed through the electrodes for 4 min using a direct current power supply, which caused exfoliation of graphite from the anode. The amount of exfoliated graphite was determined to be in the range of 0.5–0.6 g.
Thereafter, electrodes were withdrawn from the solution. In the second step, 3 g of KMnO4 was added into the reaction mixture containing exfoliated graphite. The reaction mixture was stirred at 55–60 °C using a water bath for different oxidation time (1, 2, 4, 6, 8, 10, and 12 h) to understand the effect of time on the levels of oxidation. Thereafter, the reaction mixture was cooled to room temperature and the oxidation reaction was quenched by adding 70 mL of ice water containing 2 mL of H2O2. A brownish golden solid material synthesized up to this time was separated by centrifugation and subsequently washed three times with deionized water to remove any of the unreacted material. Further, the solid material was washed with 50 mL of 30% hydrochloric acid (HCl) and 30 mL of ethanol and finally coagulated with diethyl ether. During this process, coagulation of the bunches of sheets takes place. These bunches were separated into sheets (with five to seven layers each) by sonicating the obtained material in water using a probe sonicator for 1 h and then drying at 60 °C in a Petri dish. Different GO batches were referred to as GO (1 h), GO (2 h), GO (4 h), GO (6 h), GO (8 h), GO (10 h), and GO (12 h), where the text in parentheses represents the time of oxidation. For comparison, GO was also synthesized by widely used Marcano’s method using graphite powder as a precursor according to the method developed earlier by performing oxidation for 12 h (20) and further characterized by different methods. The schematic representation of the method of synthesis is given in Figure 10.

Figure 10

Figure 10. Representation of various steps involved in the synthesis of graphene oxide.

Characterization Techniques

Powder X-ray diffraction patterns of prepared samples were recorded by a Bruker ARS D8 Advance diffractometer in the angular range of 5–90° with a scan rate of 2° min–1 and using Cu Kα (λ = 0.15404 nm) as X-ray source, operated at 40 kV. Raman spectra of the samples were obtained by an inVia Raman microscope (Renishaw) using a monochromatic laser source of wavelength λ = 514 nm. The absorption spectra of the GO samples were obtained using a Shimadzu UV-1800 spectrophotometer in the wavelength range of 200–800 nm. Fourier transform infrared (FTIR) spectroscopy of GO was performed using a Nicolet Nexus instrument to identify the functional groups present in different samples of GO. KBr pellets of the dried samples were scanned in the wavenumber range of 4000–400 cm–1 so as to obtain transmittance (%) versus wavenumber graphs. Transmission electron microscope and field emission scanning electron microscope (FE-SEM) coupled with energy-dispersive X-ray (EDX) systems were used for the analysis of the morphological characteristics of the as-synthesized GO sheets. The transmission electron microscope was operated at 200 kV, and the field emission scanning electron microscope/energy-dispersive X-ray device was operated at 15 kV. XPS analysis was conducted using PHI 5000 versa probe III.

Analysis of Functional Moieties

The Boehm titration method was used for analyzing the concentration and nature of functional groups that are introduced in the graphene skeleton during oxidation. Briefly, 0.1 g of GO sheets was dispersed in 100 mL of 0.1 M NaOH, NaHCO3, and Na2CO3 separately. The obtained dispersion was mechanically stirred for 48 h at room temperature and then filtered to separate GO sheets from solution. Thereafter, 5 mL extracts of NaOH, NaHCO3, and Na2CO3 were titrated with 0.05 M HCl using phenolphthalein as indicator. A controlled experiment without GO sheets was also performed for proper calculations.

Supporting Information

ARTICLE SECTIONS
Jump To

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsomega.8b01283.

  • Raman spectra of different GO batches and deconvoluted FTIR graphs in the wavenumber range of 1500–18500 cm–1 (PDF)

Terms & Conditions

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Author Information

ARTICLE SECTIONS
Jump To

  • Corresponding Author
  • Author
    • Navneet Kumar - Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
  • Notes
    The authors declare no competing financial interest.

References

ARTICLE SECTIONS
Jump To

This article references 61 other publications.

  1. 1
    Allen, M. J.; Tung, V. C.; B, K. R. Honeycomb Carbon A Study of Graphene. Chem. Rev. 2010, 110, 132145,  DOI: 10.1021/cr900070d
  2. 2
    Chen, D.; Feng, H.; Li, J. Graphene Oxide: Preparation, Functionalization, and Electrochemical Applications. Chem. Rev. 2012, 112, 60276053,  DOI: 10.1021/cr300115g
  3. 3
    Natarajan, J.; Madras, G.; Chatterjee, K. Development of Graphene Oxide-/Galactitol Polyester-Based Biodegradable Composites for Biomedical Applications. ACS Omega 2017, 2, 55455556,  DOI: 10.1021/acsomega.7b01139
  4. 4
    Bjerglund, E. T.; Kristensen, M. E. P.; Stambula, S.; Botton, G. A.; Pedersen, S. U.; Daasbjerg, K. Efficient Graphene Production by Combined Bipolar Electrochemical Intercalation and High-Shear Exfoliation. ACS Omega 2017, 2, 64926499,  DOI: 10.1021/acsomega.7b01057
  5. 5
    Gleason, K.; Saraf, S.; Seal, S.; Putnam, S. A. Atmospheric Deposition of Modified Graphene Oxide on Silicon by Evaporation-Assisted Deposition. ACS Omega 2018, 3, 11541158,  DOI: 10.1021/acsomega.7b01816
  6. 6
    Balandin, A. A.; Ghosh, S.; Bao, W.; Calizo, I.; Teweldebrhan, D.; Miao, F.; Lau, C. N. Superior Thermal Conductivity of Single-Layer Graphene. Nano Lett. 2008, 8, 902907,  DOI: 10.1021/nl0731872
  7. 7
    Lee, C.; Wei, X.; Kysar, J. W.; Hone, J. Measurements of the Elastic Properties and Intrinsic Strength of Monolayer Graphene. Science 2008, 321, 385388,  DOI: 10.1126/science.1157996
  8. 8
    Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L. Ultrahigh Electron Mobility in Suspended Graphene. Solid State Commun. 2008, 146, 351355,  DOI: 10.1016/j.ssc.2008.02.024
  9. 9
    Choi, W.; Lahiri, I.; Seelaboyina, R.; Kang, Y. S. Synthesis of Graphene and Its Applications: A Review. Crit. Rev. Solid State Mater. Sci. 2010, 35, 5271,  DOI: 10.1080/10408430903505036
  10. 10
    Novoselov, K. S.; Fal’ko, V. I.; Colombo, L.; Gellert, P. R.; Schwab, M. G.; Kim, K. A Roadmap for Graphene. Nature 2012, 490, 192200,  DOI: 10.1038/nature11458
  11. 11
    Wang, Y.; Li, Z.; Wang, J.; Li, J.; Lin, Y. Graphene and Graphene Oxide: Biofunctionalization and Applications in Biotechnology. Trends Biotechnol. 2011, 29, 205212,  DOI: 10.1016/j.tibtech.2011.01.008
  12. 12
    Pumera, M. Graphene-Based Nanomaterials for Energy Storage. Energy Environ. Sci. 2011, 4, 668,  DOI: 10.1039/C0EE00295J
  13. 13
    Brownson, D. A. C.; Kampouris, D. K.; Banks, C. E. An Overview of Graphene in Energy Production and Storage Applications. J. Power Sources 2011, 196, 48734885,  DOI: 10.1016/j.jpowsour.2011.02.022
  14. 14
    Kemp, K. C.; Seema, H.; Saleh, M.; Le, N. H.; Mahesh, K.; Chandra, V.; Kim, K. S. Environmental Applications Using Graphene Composites: Water Remediation and Gas Adsorption. Nanoscale 2013, 5, 31493171,  DOI: 10.1039/c3nr33708a
  15. 15
    Hummers, W. S.; Offeman, R. E. Preparation of Graphitic Oxide. J. Am. Chem. Soc. 1958, 80, 1339,  DOI: 10.1021/ja01539a017
  16. 16
    Chen, J.; Yao, B.; Li, C.; Shi, G. An Improved Hummers Method for Eco-Friendly Synthesis of Graphene Oxide. Carbon 2013, 64, 225229,  DOI: 10.1016/j.carbon.2013.07.055
  17. 17
    Chen, J.; Li, Y.; Huang, L.; Li, C.; Shi, G. High-Yield Preparation of Graphene Oxide from Small Graphite Flakes via an Improved Hummers Method with a Simple Purification Process. Carbon 2015, 81, 826834,  DOI: 10.1016/j.carbon.2014.10.033
  18. 18
    Kovtyukhova, N. I.; Ollivier, P. J.; Martin, B. R.; Mallouk, T. E.; Chizhik, S. A.; Buzaneva, E. V.; Gorchinskiy, A. D. Layer-by-Layer Assembly of Ultrathin Composite Films from Micron-Sized Graphite Oxide Sheets and Polycations. Chem. Mater. 1999, 11, 771778,  DOI: 10.1021/cm981085u
  19. 19
    Sun, J.; Yang, N.; Sun, Z.; Zeng, M.; Fu, L.; Hu, C.; Hu, S. Fully Converting Graphite into Graphene Oxide Hydrogels by Preoxidation with Impure Manganese Dioxide. ACS Appl. Mater. Interfaces 2015, 7, 2135621363,  DOI: 10.1021/acsami.5b06008
  20. 20
    Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z.; Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. Improved Synthesis of Graphene Oxide. ACS Nano 2010, 4, 48064814,  DOI: 10.1021/nn1006368
  21. 21
    Liou, Y. J.; Tsai, B. D.; Huang, W. J. An Economic Route to Mass Production of Graphene Oxide Solution for Preparing Graphene Oxide Papers. Mater. Sci., Eng. B 2015, 193, 3740,  DOI: 10.1016/j.mseb.2014.11.007
  22. 22
    Hu, Y.; Song, S.; Lopez-Valdivieso, A. Effects of Oxidation on the Defect of Reduced Graphene Oxides in Graphene Preparation. J. Colloid Interface Sci. 2015, 450, 6873,  DOI: 10.1016/j.jcis.2015.02.059
  23. 23
    Shahriary, L.; Athawale, A. A. Graphene Oxide Synthesized by Using Modified Hummers Approach. Int. J. Renew. Energy Environ. Eng. 2014, 02, 5863
  24. 24
    Wang, G.; Yang, J.; Park, J.; Gou, X.; Wang, B.; Liu, H.; Yao, J. Facile Synthesis and Characterization of Graphene Nanosheets. J. Phys. Chem. C 2008, 112, 81928195,  DOI: 10.1021/jp710931h
  25. 25
    Li, C.; Xu, Y. T.; Zhao, B.; Jiang, L.; Chen, S. G.; Xu, J. B.; Fu, X. Z.; Sun, R.; Wong, C. P. Flexible Graphene Electrothermal Films Made from Electrochemically Exfoliated Graphite. J. Mater. Sci. 2016, 51, 10431051,  DOI: 10.1007/s10853-015-9434-x
  26. 26
    Punith Kumar, M. K.; Nidhi, M.; Srivastava, C. Electrochemical Exfoliation of Graphite to Produce Graphene Using Tetrasodium Pyrophosphate. RSC Adv. 2015, 5, 2484624852,  DOI: 10.1039/C5RA01304F
  27. 27
    Kakaei, K.; Hasanpour, K. Synthesis of Graphene Oxide Nanosheets by Electrochemical Exfoliation of Graphite in Cetyltrimethylammonium Bromide and Its Application for Oxygen Reduction. J. Mater. Chem. A 2014, 2, 15428,  DOI: 10.1039/C4TA03026E
  28. 28
    Rao, K. S.; Senthilnathan, J.; Liu, Y.-F.; Yoshimura, M. Role of Peroxide Ions in Formation of Graphene Nanosheets by Electrochemical Exfoliation of Graphite. Sci. Rep. 2014, 4, 4237  DOI: 10.1038/srep04237
  29. 29
    Parvez, K.; Li, R.; Puniredd, S. R.; Hernandez, Y.; Hinkel, F.; Wang, S.; Feng, X.; Mullen, K. Electrochemically Exfoliated Graphene as Solution-Processable, Highly Conductive Electrodes for Organic Electronics. ACS Nano 2013, 7, 35983606,  DOI: 10.1021/nn400576v
  30. 30
    Su, C. Y.; Lu, A. Y.; Xu, Y.; Chen, F. R.; Khlobystov, A. N.; Li, L. J. High-Quality Thin Graphene Films from Fast Electrochemical Exfoliation. ACS Nano 2011, 5, 23322339,  DOI: 10.1021/nn200025p
  31. 31
    Mao, M.; Wang, M.; Hu, J.; Lei, G.; Chen, S.; Liu, H. Simultaneous Electrochemical Synthesis of Few-Layer Graphene Flakes on Both Electrodes in Protic Ionic Liquids. Chem. Commun. 2013, 49, 5301,  DOI: 10.1039/c3cc41909f
  32. 32
    Brodie, B. C. On the Atomic Weight of Graphite. Philos. Trans. R. Soc. London 1859, 149, 249259,  DOI: 10.1098/rstl.1859.0013
  33. 33
    Staudenmaier, L. Verfahren Zur Darstellung Der Graphitsure. Ber. Dtsch. Chem. Ges. 1898, 31, 14811487,  DOI: 10.1002/cber.18980310237
  34. 34
    Kaur, M.; Kaur, H.; Kukkar, D. Synthesis and Characterization of Graphene Oxide Using Modified Hummer ’ s Method. AIP Conf. Proc. 2018, 030180  DOI: 10.1063/1.5032515
  35. 35
    Singh, S. K.; Singh, M. K.; Kulkarni, P. P.; Sonkar, V. K.; Grácio, J. J. A.; Dash, D. Amine-Modified Graphene: Thrombo-Protective Safer Alternative to Graphene Oxide for Biomedical Applications. ACS Nano 2012, 6, 27312740,  DOI: 10.1021/nn300172t
  36. 36
    Kaladevi, G.; Meenakshi, S.; Pandian, K.; Wilson, P. Synthesis of Well-Dispersed Silver Nanoparticles on Polypyrrole/Reduced Graphene Oxide Nanocomposite for Simultaneous Detection of Toxic Hydrazine and Nitrite in Water Sources. J. Electrochem. Soc. 2017, 164, B620B631,  DOI: 10.1149/2.0611713jes
  37. 37
    López-Díaz, D.; Lopez Holgado, M.; Garcia-Fierro, J. L.; Velazquez, M. M. Evolution of the Raman Spectrum with the Chemical Composition of Graphene Oxide. J. Phys. Chem. C 2017, 121, 2048920497,  DOI: 10.1021/acs.jpcc.7b06236
  38. 38
    Mehta, J. S.; Faucett, A. C.; Sharma, A.; Mativetsky, J. M. How Reliable Are Raman Spectroscopy Measurements of Graphene Oxide. J. Phys. Chem. C 2017, 121, 1658416591,  DOI: 10.1021/acs.jpcc.7b04517
  39. 39
    Tandel, R. D.; Pawar, S. K.; Seetharamappa, J. Synthesis and Characterization of Bentonite-Reduced Graphene Oxide Composite: Application as Sensor for a Neurotransmitter, Dopamine. J. Electrochem. Soc. 2016, 163, H705H713,  DOI: 10.1149/2.0991608jes
  40. 40
    Verma, S.; Dutta, R. K. Development of Cysteine Amide Reduced Graphene Oxide (CARGO) Nano-Adsorbents for Enhanced Uranyl Ions Removal from Aqueous Medium. J. Environ. Chem. Eng. 2017, 5, 45474558,  DOI: 10.1016/j.jece.2017.08.047
  41. 41
    Cançado, L. G.; Gomes-da-Silva, M.; Ferreira, E. H. M.; Hof, F.; Kampioti, K.; Huang, K.; Penicaud, A.; Achete, C. A.; Capaz, R. B.; Jorio, A. Disentangling contributions of point and line defects in the Raman spectra of graphene-related materials. 2D Mater. 2017, 4, 025039  DOI: 10.1088/2053-1583/aa5e77
  42. 42
    Tuinstra, F.; Koenig, J. L. Raman Spectrum of Graphite. J. Chem. Phys. 1970, 53, 11261130,  DOI: 10.1063/1.1674108
  43. 43
    Guerrero-Contreras, J.; Caballero-Briones, F. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method. Mater. Chem. Phys. 2015, 153, 209220,  DOI: 10.1016/j.matchemphys.2015.01.005
  44. 44
    Kudin, K. N.; Ozbas, B.; Schniepp, H. C.; Prud, R. K.; Aksay, I. A.; Car, R.; Prud’Homme, R. K. Raman Spectra of Graphite Oxide and Functionalized Graphene Sheets. Nano Lett. 2008, 8, 3641,  DOI: 10.1021/nl071822y
  45. 45
    Minitha, C. R.; Anithaa, V. S.; Subramaniam, V.; Rajendra Kumar, R. T. Impact of Oxygen Functional Groups on Reduced Graphene Oxide-Based Sensors for Ammonia and Toluene Detection at Room Temperature. ACS Omega 2018, 3, 41054112,  DOI: 10.1021/acsomega.7b02085
  46. 46
    Paredes, J. I.; Marti, A.; Tasco, J. M. D.; Martı, A. Graphene Oxide Dispersions in Organic Solvents Graphene Oxide Dispersions in Organic Solvents. Langmuir 2008, 24, 1056010564,  DOI: 10.1021/la801744a
  47. 47
    Verma, S.; Dutta, R. K. A Facile Method of Synthesizing Ammonia Modified Graphene Oxide for Efficient Removal of Uranyl Ions from Aqueous Medium. RSC Adv. 2015, 5, 7719277203,  DOI: 10.1039/C5RA10555B
  48. 48
    Yang, Z.; Zheng, X.; Zheng, J. A Facile One-Step Synthesis of Fe2O3 Nanoparticles/Reduced Graphene Oxide for Enhanced Hydrazine Sensing. J. Electrochem. Soc. 2017, 164, B74B80,  DOI: 10.1149/2.0031704jes
  49. 49
    Wei, Y.; Jang, C. H. Liquid Crystal as Sensing Platforms for Determining the Effect of Graphene Oxide-Based Materials on Phospholipid Membranes and Monitoring Antibacterial Activity. Sens. Actuators, B 2018, 254, 7280,  DOI: 10.1016/j.snb.2017.07.057
  50. 50
    Pei, S.; Wei, Q.; Huang, K.; Cheng, H. M.; Ren, W. Green Synthesis of Graphene Oxide by Seconds Timescale Water Electrolytic Oxidation. Nat. Commun. 2018, 9, 145  DOI: 10.1038/s41467-017-02479-z
  51. 51
    Ahirwar, S.; Mallick, S.; Bahadur, D. Electrochemical Method to Prepare Graphene Quantum Dots and Graphene Oxide Quantum Dots. ACS Omega 2017, 2, 83438353,  DOI: 10.1021/acsomega.7b01539
  52. 52
    Shao, G.; Lu, Y.; Wu, F.; Yang, C.; Zeng, F.; Wu, Q. Graphene Oxide: The Mechanisms of Oxidation and Exfoliation. J. Mater. Sci. 2012, 47, 44004409,  DOI: 10.1007/s10853-012-6294-5
  53. 53
    Gupta, T. K.; Singh, B. P.; Tripathi, R. K.; Dhakate, S. R.; Singh, V. N.; Panwar, O. S.; Mathur, R. B. Superior Nano-Mechanical Properties of Reduced Graphene Oxide Reinforced Polyurethane Composites. RSC Adv. 2015, 5, 1692116930,  DOI: 10.1039/C4RA14223C
  54. 54
    Huang, N. M.; Lim, H. N.; Chia, C. H.; Yarmo, M. A.; Muhamad, M. R. Simple Room-temperature Preparation of High-yield Large-area Graphene oxide. Int. J. Nanomed. 2011, 6, 34433448,  DOI: 10.2147/IJN.S26812
  55. 55
    Lai, Q.; Zhu, S.; Luo, X.; Zou, M.; Huang, S. Ultraviolet-Visible Spectroscopy of Graphene Oxides. AIP Adv. 2012, 2, 032146  DOI: 10.1063/1.4747817
  56. 56
    Dong, L.; Yang, J.; Chhowalla, M.; Loh, K. P. Synthesis and Reduction of Large Sized Graphene Oxide Sheets. Chem. Soc. Rev. 2017, 46, 73067316,  DOI: 10.1039/C7CS00485K
  57. 57
    Wilson, N. R.; Pandey, P. A.; Beanland, R.; Young, R. J.; Kinloch, I. A.; Gong, L.; Liu, Z.; Suenaga, K.; Rourke, J. P.; York, S. J.; Sloan, J. Graphene Oxide: Structural Analysis and Application as a Highly Transparent Support for Electron Microscopy. ACS Nano 2009, 3, 25472556,  DOI: 10.1021/nn900694t
  58. 58
    Mkhoyan, K. A.; Contryman, A. W.; Silcox, J.; Stewart, D. A.; Eda; Mattevi, C.; Miller, S.; Chhowalla, M. Atomic and Electronic Structure of Graphene-Oxide. Nano Lett. 2009, 9, 10581063,  DOI: 10.1021/nl8034256
  59. 59
    Krishnamoorthy, K.; Veerapandian, M.; Yun, K.; Kim, S.-J. The Chemical and Structural Analysis of Graphene Oxide with Different Degrees of Oxidation. Carbon 2013, 53, 3849,  DOI: 10.1016/j.carbon.2012.10.013
  60. 60
    Dreyer, D. R.; Park, S.; Bielawski, C. W.; Ruoff, R. S. The Chemistry of Graphene Oxide. Chem. Soc. Rev. 2010, 39, 228240,  DOI: 10.1039/B917103G
  61. 61
    Dimiev, A. M.; Tour, J. M. Mechanism of Graphene Oxide Formation. ACS Nano 2014, 8, 30603068,  DOI: 10.1021/nn500606a

Cited By

ARTICLE SECTIONS
Jump To

This article is cited by 110 publications.

  1. Martins O. Omorogie, Brigitte Helmreich. Exploring the Potential of Amino-Functionalized Zeolite Series/H3PO4-Biochar for Environmental Microplastic Removal. Industrial & Engineering Chemistry Research 2024, Article ASAP.
  2. Oktaviardi Bityasmawan Abdillah, Octia Floweri, Muhammad Alief Irham, Akfiny Hasdi Aimon, Takashi Ogi, Ferry Iskandar. Structural Modulation of Exfoliated Graphene via a Facile Postultrasonication Treatment toward Enhanced Electrochemical Properties of Supercapacitor Electrode. Energy & Fuels 2022, 36 (23) , 14453-14463. https://doi.org/10.1021/acs.energyfuels.2c02809
  3. Wei-Wen Liu, Azizan Aziz. Review on the Effects of Electrochemical Exfoliation Parameters on the Yield of Graphene Oxide. ACS Omega 2022, 7 (38) , 33719-33731. https://doi.org/10.1021/acsomega.2c04099
  4. Supatinee Kongkaew, Lingyin Meng, Warakorn Limbut, Proespichaya Kanatharana, Panote Thavarungkul, Wing Cheung Mak. Evaluation on the Intrinsic Physicoelectrochemical Attributes and Engineering of Micro-, Nano-, and 2D-Structured Allotropic Carbon-Based Papers for Flexible Electronics. Langmuir 2021, 37 (49) , 14302-14313. https://doi.org/10.1021/acs.langmuir.1c02121
  5. Krishnendu Pramanik, Pavel Sengupta, Shalini Dasgupta, Pallab Datta, Priyabrata Sarkar. Electrochemical Column Cell for Continuous Oxidative Inactivation of Pathogens and Reductive Removal of Toxic Heavy Metals. ACS Applied Materials & Interfaces 2021, 13 (27) , 32402-32414. https://doi.org/10.1021/acsami.1c04471
  6. Surendran Pandiyan, Lakshmanan Arumugam, Sakthy Priya Srirengan, Rameshkumar Pitchan, Pushpalatha Sevugan, Karthik Kannan, Geetha Pitchan, Tejaswi Ashok Hegde, Vinitha Gandhirajan. Biocompatible Carbon Quantum Dots Derived from Sugarcane Industrial Wastes for Effective Nonlinear Optical Behavior and Antimicrobial Activity Applications. ACS Omega 2020, 5 (47) , 30363-30372. https://doi.org/10.1021/acsomega.0c03290
  7. Navneet Kumar, Vimal Chandra Srivastava. Dimethyl Carbonate Synthesis via Transesterification of Propylene Carbonate Using an Efficient Reduced Graphene Oxide-Supported ZnO Nanocatalyst. Energy & Fuels 2020, 34 (6) , 7455-7464. https://doi.org/10.1021/acs.energyfuels.0c01091
  8. Nisha Yadav, Vedha Kallur, Dwaipayan Chakraborty, Priya Johari, Bimlesh Lochab. Control of Functionalities in GO: Effect of Bronsted Acids as Supported by Ab Initio Simulations and Experiments. ACS Omega 2019, 4 (5) , 9407-9418. https://doi.org/10.1021/acsomega.9b00676
  9. George V. Theodorakopoulos, Dionysios S. Karousos, Jan Benra, Stefan Forero, Ruben Hammerstein, Andreas A. Sapalidis, Fotios K. Katsaros, Tim Schubert, Evangelos P. Favvas. Well-established carbon nanomaterials: modification, characterization and dispersion in different solvents. Journal of Materials Science 2024, 354 https://doi.org/10.1007/s10853-024-09413-x
  10. Dipak Kumar Sahoo, Biswajit Dalai, Arun Kumar Mohanty, Chhatrapati Parida. Novel approach for modification of graphene oxide using continuous wave-laser obtained from surgical laser diode. Radiation Effects and Defects in Solids 2024, , 1-24. https://doi.org/10.1080/10420150.2024.2309199
  11. Yejin Park, Hyejin Kim, Jaeyoon Song, Sehyeon Kim, Byung Chul Lee, Jinsik Kim. Dielectrophoretic force-induced wrinkling of graphene oxide: Enhancing electrical conductivity and expanding biosensing applications. Biosensors and Bioelectronics 2024, 246 , 115867. https://doi.org/10.1016/j.bios.2023.115867
  12. Miroslav Huskić, Dejan Kepić, Duška Kleut, Miran Mozetič, Alenka Vesel, Alojz Anžlovar, Danica Bajuk Bogdanović, Svetlana Jovanović. The Influence of Reaction Conditions on the Properties of Graphene Oxide. Nanomaterials 2024, 14 (3) , 281. https://doi.org/10.3390/nano14030281
  13. Rohit Srivastava, Pankaj Kumar Singh, Pradeep Kumar Singh. Evaluation of graphene microstructural and optical properties affected by high-temperature annealing and rapid cooling in a nitrogen-rich environment. Modern Physics Letters B 2024, 17 https://doi.org/10.1142/S0217984924501847
  14. Damilola O. Akamo, Kai Li, Tugba Turnaoglu, Navin Kumar, Yuzhan Li, Collin Pekol, Nitish Bibhanshu, Monojoy Goswami, Jason Hirschey, Tim J. LaClair, David J. Keffer, Orlando Rios, Kyle R. Gluesenkamp. Enhanced thermal reliability and performance of calcium chloride hexahydrate phase change material using cellulose nanofibril and graphene nanoplatelet. Journal of Energy Storage 2024, 75 , 109560. https://doi.org/10.1016/j.est.2023.109560
  15. Abdullah S. Alshammari. Controlling Dye Adsorption Kinetics of Graphene Oxide Nano-Sheets via Optimized Oxidation Treatment. Crystals 2024, 14 (1) , 49. https://doi.org/10.3390/cryst14010049
  16. Navneet Kumar, Swati Verma, Pankaj Kumar, Abbas Ahmad Khan, Jinsub Park, Vimal Chandra Srivastava. Efficient one-pot two-step electrochemical synthesis of highly oxidized graphene oxide for enhanced energy and environmental applications: Structure elucidation through DFT simulations. Carbon 2024, 218 , 118722. https://doi.org/10.1016/j.carbon.2023.118722
  17. V. M. Sonin, E. I. Zhimulev, A. I. Chepurov, S. V. Goryainov, S. A. Gromilov, I. A. Gryaznov, A. A. Chepurov, A. A. Tomilenko. Synthesis of diamond from polycyclic aromatic hydrocarbons (anthracene) in the presence of an Fe,Ni-melt at 5.5 GPa and 1450 °C. CrystEngComm 2024, 69 https://doi.org/10.1039/D3CE01220D
  18. Souad Abou Zeid, Selma Bencherif, Rasta Ghasemi, Rituporn Gogoi, Yamina Chouli, Matthieu Gervais, Diana Dragoe, Jalal Ghilane, Prem Felix Siril, Samy Remita. Radiation induced reduction of graphene oxide: a dose effect study. New Journal of Chemistry 2024, 324 https://doi.org/10.1039/D4NJ00167B
  19. Y. Melikyan, H. Gharagulyan, A. Vasil'ev, V. Hayrapetyan, M. Zhezhu, A. Simonyan, D.A. Ghazaryan, M.S. Torosyan, A. Kharatyan, J. Michalicka, M. Yeranosyan. E-beam induced micropattern generation and amorphization of L-cysteine-functionalized graphene oxide nano-composites. Colloid and Interface Science Communications 2024, 58 , 100766. https://doi.org/10.1016/j.colcom.2024.100766
  20. Nafisur Rahman, Abdur Raheem. Mechanistic investigation of levofloxacin adsorption on Fe (III)-tartaric acid/xanthan gum/graphene oxide/polyacrylamide hydrogel: Box-Behnken design and Taguchi method for optimization. Journal of Industrial and Engineering Chemistry 2023, 127 , 110-124. https://doi.org/10.1016/j.jiec.2023.06.044
  21. S. García-Carpintero, V. Jehová González, J. Frontiñán-Rubio, A. Esteban-Arranz, E. Vázquez, M. Durán-Prado. Screening the micronucleus assay for reliable estimation of the genotoxicity of graphene and other 2D materials. Carbon 2023, 215 , 118426. https://doi.org/10.1016/j.carbon.2023.118426
  22. Qian Zhang, Xiao-qi Chen, Xin-yue Lan, Jun-ming Hong. Modulating Cu valence state in Cu and graphene oxide composites for electrocatalytic tetracycline hydrochloride degradation. Environmental Science and Pollution Research 2023, 30 (52) , 112252-112266. https://doi.org/10.1007/s11356-023-30269-2
  23. Vinicius Rossa, Sancler da Costa Vasconcelos, Gisel Chenard Díaz, Josué de Almeida Resende, João Pedro Reys Mattos, Vinicius Gomes da Costa Madriaga, Fernanda Franco Massante, Yordanka Reyes Cruz, Juan Lucas Nachez, Yutao Xing, Eduardo Ariel Ponzio, Thiago de Melo Lima. Solketal Production Using Eco-Friendly Reduced Graphene Oxide as the Catalyst. Catalysts 2023, 13 (11) , 1427. https://doi.org/10.3390/catal13111427
  24. K. Lakshmanamoorthy, S. Manivannan. Synthesis of few-layer graphene through simultaneous ultrasonication and electrochemical exfoliation in a Bronsted acidic ionic liquid [NMP] [HSO4] aqueous electrolyte for NH3 vapor sensing. Carbon Letters 2023, 306 https://doi.org/10.1007/s42823-023-00627-8
  25. Abolfazl Jafari, Hamid Reza Mortaheb. Incorporating graphene nanosheets in PDMS membrane: Effects of filler functionalization on pervaporation performance. Chemical Engineering and Processing - Process Intensification 2023, 191 , 109464. https://doi.org/10.1016/j.cep.2023.109464
  26. Jean Valdir Uchôa Teixeira, Gabriel Junior Cavalcante Pimentel, Adriana Alencar Santos, Leonardo Francisco Gonçalves Dias, Valmor Roberto Mastelaro, Paulo Noronha Lisboa-Filho. Partially reduced graphene oxide produced by glucose in alkaline conditions using probe sonication: the role of the base in reduction. Journal of Materials Research and Technology 2023, 26 , 1785-1797. https://doi.org/10.1016/j.jmrt.2023.07.211
  27. Pankaj Kumar Singh, Pradeep Kumar Singh, Kamal Sharma, Soni Kumari. Effect of thermal annealing on physical, structural, and performance variation of graphene oxide: A review. Modern Physics Letters B 2023, 37 (24) https://doi.org/10.1142/S0217984923300016
  28. Riccardo Castagna, Cristiano Riminesi, Andrea Di Donato, Rachele Castaldo, Roberto Avolio, Luigi Montalto, Francesco Vita, Oriano Francescangeli, Daniele Eugenio Lucchetta. On the Asymmetry in Photo-Induced Motion of Graphene-Oxide Paper. Coatings 2023, 13 (8) , 1310. https://doi.org/10.3390/coatings13081310
  29. Sagar Ingavale, Phiralang Marbaniang, Manoj Palabathuni, Vaibhav Namdev Kale, Nimai Mishra. Decoration of boron nanoparticles on a graphene sheet for ammonia production from nitrate. Nanoscale 2023, 15 (27) , 11497-11505. https://doi.org/10.1039/D3NR01089A
  30. Yinsha Wei, Zeeshan Haider, Yizhen Yu, Bingzhi Li, Haili Niu, Ri Qiu, Yibo Ouyang, Jie Liu. Bioinspired corrosion inhibition for printed circuit board: implications of dendritic Sn-ZIF-LIS coating on Cu metal. Journal of Materials Science 2023, 58 (25) , 10539-10554. https://doi.org/10.1007/s10853-023-08673-3
  31. Aruna K Kunhiraman, Muhammad Rahees Puthalath, R Ajay Rakkesh. Hybrid SrMoO 4 @rGO electrocatalyst for hydrogen evolution reaction in acid medium. Nanomaterials and Energy 2023, 12 (3) , 92-99. https://doi.org/10.1680/jnaen.23.00047
  32. Lia Destiarti, Riyanto Riyanto, Roto Roto, Mudasir Mudasir. Electrolyte effect in electrochemical exfoliation of graphite. Materials Chemistry and Physics 2023, 302 , 127713. https://doi.org/10.1016/j.matchemphys.2023.127713
  33. Didem Aycan, Fatma Karaca, Neslihan Alemdar. Development of hyaluronic acid-based electroconductive hydrogel as a sensitive non-enzymatic glucose sensor. Materials Today Communications 2023, 35 , 105745. https://doi.org/10.1016/j.mtcomm.2023.105745
  34. Chandni Sharma, Ashish K. Shukla, Mohini Verma, Manik Bathla, Amitabha Acharya. Preferential disruption of E. coli biofilm via ratiometric detection and targeting of extracellular matrix using graphene-oxide-conjugated red-emitting fluorescent copper nanoclusters. Environmental Science: Nano 2023, 10 (4) , 1077-1095. https://doi.org/10.1039/D2EN00899H
  35. Baskar Thangaraj, Fatima Mumtaz, Yawar Abbas, Dalaver H. Anjum, Pravin Raj Solomon, Jamal Hassan. Synthesis of Graphene Oxide from Sugarcane Dry Leaves by Two-Stage Pyrolysis. Molecules 2023, 28 (8) , 3329. https://doi.org/10.3390/molecules28083329
  36. Yingjie Bu, Beom Soo Kim. Eco-friendly production of functionalized few-layer graphene using coffee waste extract and in-situ growth of copper oxide nanoparticles. Journal of Environmental Chemical Engineering 2023, 11 (2) , 109350. https://doi.org/10.1016/j.jece.2023.109350
  37. Yu-Xuan Liou, Shiue-Lin Li, Kun-Yi Hsieh, Sin-Jie Li, Li-Jie Hu. Investigating the Extracellular-Electron-Transfer Mechanisms and Kinetics of Shewanella decolorationis NTOU1 Reducing Graphene Oxide via Lactate Metabolism. Bioengineering 2023, 10 (3) , 311. https://doi.org/10.3390/bioengineering10030311
  38. Wen Sun, Yaoliang Hong, Tian Li, Huaqiang Chu, Junxia Liu, Li Feng, Mehidi Baghayeri. Biogenic synthesis of reduced graphene oxide decorated with silver nanoparticles (rGO/Ag NPs) using table olive (olea europaea) for efficient and rapid catalytic reduction of organic pollutants. Chemosphere 2023, 310 , 136759. https://doi.org/10.1016/j.chemosphere.2022.136759
  39. Navneet Kumar, Uijin Jung, Bomseumin Jung, Jinsub Park, Mu. Naushad. Zinc hydroxystannate/zinc-tin oxide heterojunctions for the UVC-assisted photocatalytic degradation of methyl orange and tetracycline. Environmental Pollution 2023, 316 , 120353. https://doi.org/10.1016/j.envpol.2022.120353
  40. Muhammad Arifin, Oktaviardi Bityasmawan Abdillah, Retno Maharsi, Octia Floweri, Ferry Iskandar. Preliminary study of ultrasonication effect on the electrical properties of electrochemically exfoliated graphite. 2023, 020004. https://doi.org/10.1063/5.0129949
  41. Ashish Suttee, Prashant Tandale. Graphene oxide based multifunctional nano composite for cancer theranostics: Present clinical and regulatory breakthroughs. 2023, 020201. https://doi.org/10.1063/5.0162990
  42. Anjali, Twinkle, Sonal Rattan, Manpreet Kaur, Suresh Kumar, J. K. Goswamy. Synergistic effect of reduced graphene oxide and carbon nanotubes for improved supercapacitive performance electrodes. Journal of Materials Science: Materials in Electronics 2022, 33 (36) , 26841-26851. https://doi.org/10.1007/s10854-022-09349-5
  43. Tran Van Khai, Le Ngoc Long, Nguyen Hoang Thien Khoi, Nguyen Hoc Thang. Effects of Hydrothermal Reaction Time on the Structure and Optical Properties of ZnO/Graphene Oxide Nanocomposites. Crystals 2022, 12 (12) , 1825. https://doi.org/10.3390/cryst12121825
  44. Hessamaddin Sohrabi, Omid Arbabzadeh, Pegah Khaaki, Mir Reza Majidi, Alireza Khataee, Sang Woo Joo. Emerging electrochemical sensing and biosensing approaches for detection of Fumonisins in food samples. Critical Reviews in Food Science and Nutrition 2022, 62 (31) , 8761-8776. https://doi.org/10.1080/10408398.2021.1932723
  45. Agnieszka Kałamaga, Maria Carmen Román-Martínez, Maria Angeles Lillo-Ródenas, Rafał Jan Wróbel. The Influence of NH4NO3 and NH4ClO4 on Porous Structure Development of Activated Carbons Produced from Furfuryl Alcohol. Molecules 2022, 27 (22) , 7860. https://doi.org/10.3390/molecules27227860
  46. Fahimeh Shamseali, Farzaneh Mohammadi, Hamidreza Pourzamani, Mahsa Janati, . Electrochemical Denitrification of Synthetic Aqueous Solution and Actual Contaminated Well Water: RSM Modeling, Kinetic Study, Monte Carlo Optimization, and Sensitivity Analysis. International Journal of Chemical Engineering 2022, 2022 , 1-15. https://doi.org/10.1155/2022/1374993
  47. Bhaskar Anand, Vanish Kumar, Sherif A. Younis, Ki-Hyun Kim. HKUST-1 infused woven cotton filter for enhanced adsorptive removal of toluene vapor from gaseous streams. Separation and Purification Technology 2022, 299 , 121743. https://doi.org/10.1016/j.seppur.2022.121743
  48. Dao Thi Nguyet Nga, Nguyen Le Nhat Trang, Van-Tuan Hoang, Xuan-Dinh Ngo, Pham Tuyet Nhung, Doan Quang Tri, Nguyen Duy Cuong, Pham Anh Tuan, Tran Quang Huy, Anh-Tuan Le. Elucidating the roles of oxygen functional groups and defect density of electrochemically exfoliated GO on the kinetic parameters towards furazolidone detection. RSC Advances 2022, 12 (43) , 27855-27867. https://doi.org/10.1039/D2RA04147B
  49. K. Lakshmanamoorthy, S. Prabhu, V. Ravikumar, S. Manivannan. Effect of Ionic Liquid Anions in Tunning the Morphology and Size of Ag in rGO-Ag Nanocomposites: Anticancer Activity of the Composites Against A549 Lung Cancer Cells. Journal of Inorganic and Organometallic Polymers and Materials 2022, 32 (9) , 3417-3428. https://doi.org/10.1007/s10904-022-02453-3
  50. Peyman Mohammadzadeh Jahani, Fariba Garkani Nejad, Zahra Dourandish, Mostafa Poursoltani Zarandi, Mohammad Mahdi Safizadeh, Somayeh Tajik, Hadi Beitollahi. A modified carbon paste electrode with N-rGO/CuO nanocomposite and ionic liquid for the efficient and cheap voltammetric sensing of hydroquinone in water specimens. Chemosphere 2022, 302 , 134712. https://doi.org/10.1016/j.chemosphere.2022.134712
  51. Pankaj Kumar Singh, Kamal Sharma, Pradeep Kumar Singh. Electro-magneto-chemical synthesis and characterization of thermally reduced graphene oxide: Influence of magnetic field and cyclic thermal loading on microstructural properties. Journal of Solid State Chemistry 2022, 312 , 123219. https://doi.org/10.1016/j.jssc.2022.123219
  52. Pankaj Kumar Singh, Pradeep Kumar Singh, Kamal Sharma. Electrochemical synthesis and characterization of thermally reduced graphene oxide: Influence of thermal annealing on microstructural features. Materials Today Communications 2022, 32 , 103950. https://doi.org/10.1016/j.mtcomm.2022.103950
  53. Rebeca Arambula-Maldonado, Kibret Mequanint. Carbon-based electrically conductive materials for bone repair and regeneration. Materials Advances 2022, 3 (13) , 5186-5206. https://doi.org/10.1039/D2MA00001F
  54. Nguyen Thi Thuy Linh, Tran Chau Diep, Tran Tuong Vy, Nguyen Minh Dat, Dinh Ngoc Trinh, Doan Ba Thinh, Nguyen Duc Viet, Nguyen Duy Hai, Le Minh Huong, Ninh Thi Tinh, Mai Thanh Phong, Nguyen Huu Hieu. Cotton fabric coated with graphene-based silver nanoparticles: synthesis, modification, and antibacterial activity. Cellulose 2022, 29 (11) , 6405-6424. https://doi.org/10.1007/s10570-022-04659-7
  55. Navneet Kumar, Swati Verma, Jinsub Park, Vimal Chandra Srivastava, Mu. Naushad. Evaluation of photocatalytic performances of PEG and PVP capped zinc sulfide nanoparticles towards organic environmental pollutant in presence of sunlight. Chemosphere 2022, 298 , 134281. https://doi.org/10.1016/j.chemosphere.2022.134281
  56. Mohammad Hossein Sadeghi, Hamid Reza Mortaheb, Kourosh Tabar Heidar, Fausto Gallucci. Dehydration of isopropanol by poly(vinyl alcohol) hybrid membrane containing oxygen-plasma treated graphene oxide in pervaporation process. Chemical Engineering Research and Design 2022, 183 , 318-330. https://doi.org/10.1016/j.cherd.2022.05.023
  57. Mahnaz Movafaghi Ardestani, Shokouh Mahpishanian, Bahar Forouzesh Rad, Mehran Janmohammadi, Majid Baghdadi. Preparation and characterization of room-temperature chemically expanded graphite: Application for cationic dye removal. Korean Journal of Chemical Engineering 2022, 39 (6) , 1496-1506. https://doi.org/10.1007/s11814-022-1084-5
  58. Pankaj Kumar Singh, Kamal Sharma, Pradeep Kumar Singh. A low cost, bulk synthesis of the thermally reduced graphene oxide in an aqueous solution of sulphuric acid & hydrogen peroxide via electrochemical method. Inorganic Chemistry Communications 2022, 140 , 109378. https://doi.org/10.1016/j.inoche.2022.109378
  59. Balkis Hazmi, Umer Rashid, Sibudjing Kawi, Wan Nur Aini Wan Mokhtar, Thomas Choong Shean Yaw, Bryan R. Moser, Ali Alsalme. Palm fatty acid distillate esterification using synthesized heterogeneous sulfonated carbon catalyst from plastic waste: Characterization, catalytic efficacy and stability, and fuel properties. Process Safety and Environmental Protection 2022, 162 , 1139-1151. https://doi.org/10.1016/j.psep.2022.05.001
  60. Pratiksha M Biranje, Ashwin W Patwardhan, Jyeshtharaj B Joshi, Kinshuk Dasgupta. Exfoliated graphene and its derivatives from liquid phase and their role in performance enhancement of epoxy matrix composite. Composites Part A: Applied Science and Manufacturing 2022, 156 , 106886. https://doi.org/10.1016/j.compositesa.2022.106886
  61. Kehinde Shola Obayomi, Sie Yon Lau, Michael Danquah, Tung Chiong, Masahiro Takeo. Advances in graphene oxide based nanobiocatalytic technology for wastewater treatment. Environmental Nanotechnology, Monitoring & Management 2022, 17 , 100647. https://doi.org/10.1016/j.enmm.2022.100647
  62. Qian Shan, Jie Tian, Qihui Ding, Wei Wu. Electrochemical sensor based on metal-free materials composed of graphene and graphene oxide for sensitive detection of cadmium ions in water. Materials Chemistry and Physics 2022, 284 , 126064. https://doi.org/10.1016/j.matchemphys.2022.126064
  63. Swati Verma, Ki-Hyun Kim, Navneet Kumar, Satya Sundar Bhattacharya, Mu. Naushad, Raj Kumar Dutta. Amine-amide functionalized graphene oxide sheets as bifunctional adsorbent for the removal of polar organic pollutants. Journal of Hazardous Materials 2022, 429 , 128308. https://doi.org/10.1016/j.jhazmat.2022.128308
  64. R. Ranjith, S. Ravikumar, V. Pandiyan, Umamaheswari Rajaji, Khamael M. Abualnaja, Taghrid S. Alomar, Najla AlMasoud, Mohmed Ouladsmne. Synergistic photocatalytic removal of organic pollutants in the aqueous medium using TiO2–Co3O4 decorated graphene oxide nanocomposite. Journal of Materials Science: Materials in Electronics 2022, 33 (12) , 9438-9447. https://doi.org/10.1007/s10854-021-07388-y
  65. Ailing Yang, Yue Su, Zhenzhong Zhang, Huaidong Wang, Chong Qi, Shaoguo Ru, Jun Wang. Preparation of Graphene Quantum Dots by Visible-Fenton Reaction and Ultrasensitive Label-Free Immunosensor for Detecting Lipovitellin of Paralichthys Olivaceus. Biosensors 2022, 12 (4) , 246. https://doi.org/10.3390/bios12040246
  66. Swati Verma, Raj Kumar Dutta. Sunlight assisted photocatalytic removal of trypan blue dye using g-carbon nitrides sheets as sunlight-active photocatalyst. Nanotechnology for Environmental Engineering 2022, 7 (1) , 67-74. https://doi.org/10.1007/s41204-021-00191-4
  67. Swati Verma, Dipendra Singh Mal, Paulo Roberto de Oliveira, Bruno Campos Janegitz, Jai Prakash, Raju Kumar Gupta. A facile synthesis of novel polyaniline/graphene nanocomposite thin films for enzyme-free electrochemical sensing of hydrogen peroxide. Molecular Systems Design & Engineering 2022, 7 (2) , 158-170. https://doi.org/10.1039/D1ME00130B
  68. Oindrila Hossain, Ehsanur Rahman, Hridoy Roy, Md. Shafiul Azam, Shoeb Ahmed. Synthesis, characterization, and comparative assessment of antimicrobial properties and cytotoxicity of graphene‐, silver‐, and zinc‐based nanomaterials. Analytical Science Advances 2022, 3 (1-2) , 54-63. https://doi.org/10.1002/ansa.202100041
  69. Abolfazal Jafari, Hamid Reza Mortaheb, Fausto Gallucci. Performance of octadecylamine-functionalized graphene oxide nanosheets in polydimethylsiloxane mixed matrix membranes for removal of toluene from water by pervaporation. Journal of Water Process Engineering 2022, 45 , 102497. https://doi.org/10.1016/j.jwpe.2021.102497
  70. Bo Zhong, Panyong Kuang, Jiaguo Yu. Graphene oxide: Synthesis and properties. 2022, 31-64. https://doi.org/10.1016/B978-0-12-824526-2.00002-7
  71. Swati Verma, Ki-Hyun Kim. Graphene-based materials for the adsorptive removal of uranium in aqueous solutions. Environment International 2022, 158 , 106944. https://doi.org/10.1016/j.envint.2021.106944
  72. K. Lakshmanamoorthy, S. Manivannan. NMP-HSO4 ionic liquid assist preparation of Ag/AgCl decorated rGO for visible light photocatalytic degradation of methylene blue. Materials Today: Proceedings 2022, 68 , 573-578. https://doi.org/10.1016/j.matpr.2022.08.300
  73. Irina Zarafu, Carmen Limban, Cristiana Radulescu, Ioana Daniela Dulama, Diana Camelia Nuta, Cornel Chirita, Mariana Carmen Chifiriuc, Carmellina Daniela Badiceanu, Marcela Popa, Coralia Bleotu, Laura Denisa Dragu, Raluca Maria Stirbescu, Ioan Alin Bucurica, Sorina Geanina Stanescu, Petre Ionita. Novel Structures of Functionalized Graphene Oxide with Hydrazide: Characterization and Bioevaluation of Antimicrobial and Cytocompatibility Features. Coatings 2022, 12 (1) , 45. https://doi.org/10.3390/coatings12010045
  74. Navneet Kumar, Vimal Chandra Srivastava. La2O3 nanorods - reduced graphene oxide composite as a novel catalyst for dimethyl carbonate production via transesterification route. Materials Today Communications 2021, 29 , 102974. https://doi.org/10.1016/j.mtcomm.2021.102974
  75. Ravikumar Thimmappa, Manu Gautam, Zahid M. Bhat, Abdul Raafik Arattu Thodika, Mruthunjayachari C. Devendrachari, Sanchayita Mukhopadhyay, Neethu Christudas Dargily, Musthafa Ottakam Thotiyl. An atmospheric water electrolyzer for decentralized green hydrogen production. Cell Reports Physical Science 2021, 2 (11) , 100627. https://doi.org/10.1016/j.xcrp.2021.100627
  76. Manolito G. Ybañez, Drexel H. Camacho. Designing hydrophobic bacterial cellulose film composites assisted by sound waves. RSC Advances 2021, 11 (52) , 32873-32883. https://doi.org/10.1039/D1RA02908H
  77. Ajibola A. Bayode, Eny Maria Vieira, Roshila Moodley, Samson Akpotu, Andrea S.S. de Camargo, Despo Fatta-Kassinos, Emmanuel I. Unuabonah. Tuning ZnO/GO p-n heterostructure with carbon interlayer supported on clay for visible-light catalysis: Removal of steroid estrogens from water. Chemical Engineering Journal 2021, 420 , 127668. https://doi.org/10.1016/j.cej.2020.127668
  78. Bhaskar Anand, Jan E. Szulejko, Ki-Hyun Kim, Sherif A. Younis. Proof of concept for CUK family metal-organic frameworks as environmentally-friendly adsorbents for benzene vapor. Environmental Pollution 2021, 285 , 117491. https://doi.org/10.1016/j.envpol.2021.117491
  79. Navneet Kumar, Vimal Chandra Srivastava. Dimethyl carbonate production via transesterification reaction using nitrogen functionalized graphene oxide nanosheets. Renewable Energy 2021, 175 , 1-13. https://doi.org/10.1016/j.renene.2021.04.111
  80. Hirakendu Basu, Shweta Singh, Manisha Venkatesh, Mehzabin Vivek Pimple, Rakesh Kumar Singhal. Graphene oxide-MnO2-goethite microsphere impregnated alginate: A novel hybrid nanosorbent for As (III) and As (V) removal from groundwater. Journal of Water Process Engineering 2021, 42 , 102129. https://doi.org/10.1016/j.jwpe.2021.102129
  81. Swati Verma, Sherif A. Younis, Ki-Hyun Kim, Fan Dong. Anisotropic ZnO nanostructures and their nanocomposites as an advanced platform for photocatalytic remediation. Journal of Hazardous Materials 2021, 415 , 125651. https://doi.org/10.1016/j.jhazmat.2021.125651
  82. Kyudeok Oh, Zhenghui Shen, Soojin Kwon, Martti Toivakka. Thermal properties of graphite/salt hydrate phase change material stabilized by nanofibrillated cellulose. Cellulose 2021, 28 (11) , 6845-6856. https://doi.org/10.1007/s10570-021-03936-1
  83. Savisha Mahalingam, Abreeza Manap, Azimah Omar, Foo Wah Low, N.F. Afandi, Chin Hua Chia, Nasrudin Abd Rahim. Functionalized graphene quantum dots for dye-sensitized solar cell: Key challenges, recent developments and future prospects. Renewable and Sustainable Energy Reviews 2021, 144 , 110999. https://doi.org/10.1016/j.rser.2021.110999
  84. Mahesh P More, Prashant K Deshmukh. Quality by design approach for the synthesis of graphene oxide nanosheets using full factorial design with enhanced delivery of Gefitinib nanocrystals. Materials Research Express 2021, 8 (7) , 075602. https://doi.org/10.1088/2053-1591/ac144b
  85. Muthuchamy Maruthupandy, Govindan Rajivgandhi, Thillaichidambaram Muneeswaran, Muthusamy Anand, Franck Quero. Highly efficient antibacterial activity of graphene/chitosan/magnetite nanocomposites against ESBL-producing Pseudomonas aeruginosa and Klebsiella pneumoniae. Colloids and Surfaces B: Biointerfaces 2021, 202 , 111690. https://doi.org/10.1016/j.colsurfb.2021.111690
  86. Zhenghui Shen, Soojin Kwon, Hak Lae Lee, Martti Toivakka, Kyudeok Oh. Enhanced thermal energy storage performance of salt hydrate phase change material: Effect of cellulose nanofibril and graphene nanoplatelet. Solar Energy Materials and Solar Cells 2021, 225 , 111028. https://doi.org/10.1016/j.solmat.2021.111028
  87. I I Edward, N Abdul Manaf, S A Tahir Abdul Muthalib, M R Musram Rakunman, L.S. Tan, T Tsuji. Synthesis of graphene oxide via electrochemical process: A short review towards flexible synthesis method. IOP Conference Series: Materials Science and Engineering 2021, 1142 (1) , 012019. https://doi.org/10.1088/1757-899X/1142/1/012019
  88. Oktaviardi Bityasmawan Abdillah, Octia Floweri, Tirta Rona Mayangsari, Sigit Puji Santosa, Takashi Ogi, Ferry Iskandar. Effect of H 2 SO 4 /H 2 O 2 pre-treatment on electrochemical properties of exfoliated graphite prepared by an electro-exfoliation method. RSC Advances 2021, 11 (18) , 10881-10890. https://doi.org/10.1039/D0RA10115J
  89. Mohamed S. Selim, Sherif A. El-Safty, Mohamed A. Abbas, Mohamed A. Shenashen. Facile design of graphene oxide-ZnO nanorod-based ternary nanocomposite as a superhydrophobic and corrosion-barrier coating. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2021, 611 , 125793. https://doi.org/10.1016/j.colsurfa.2020.125793
  90. Suresh Kumar, Twinkle, Manpreet Kaur. Carbon nanotube-derived highly conductive graphene nanoribbons for electronic applications. Materials Chemistry and Physics 2021, 259 , 123967. https://doi.org/10.1016/j.matchemphys.2020.123967
  91. Anton Popov, Ruta Aukstakojyte, Justina Gaidukevic, Viktorija Lisyte, Asta Kausaite-Minkstimiene, Jurgis Barkauskas, Almira Ramanaviciene. Reduced Graphene Oxide and Polyaniline Nanofibers Nanocomposite for the Development of an Amperometric Glucose Biosensor. Sensors 2021, 21 (3) , 948. https://doi.org/10.3390/s21030948
  92. S Verma, Ki-Hyun Kim, N Kumar, Sarmistha Paul, M Naushad, R Dutta. Amine-Amide Functionalized Graphene Oxide Sheets as Bifunctional Adsorbent for the Removal of Polar Organic Pollutants. SSRN Electronic Journal 2021, 21 https://doi.org/10.2139/ssrn.3969007
  93. Le Li, Dan Zhang, Jianping Deng, Qin Kang, Zhifeng Liu, Junfei Fang, Yuchun Gou. Review—Progress of Research on the Preparation of Graphene Oxide via Electrochemical Approaches. Journal of The Electrochemical Society 2020, 167 (15) , 155519. https://doi.org/10.1149/1945-7111/abbbc0
  94. Dulce K. Becerra-Paniagua, Dagoberto Cabrera-German, Evelyn B. Díaz-Cruz, Zeuz Montiel-González, M. Sotelo-Lerma, Hailin Hu. Dispersion degree and sheet spacing control of graphene products via oxygen functionalities and its effect on electrical conductivities of P3HT-graphene composite coatings. Journal of Materials Science: Materials in Electronics 2020, 31 (22) , 19623-19637. https://doi.org/10.1007/s10854-020-04489-y
  95. Shirong Shuai, Yu Liu, Cong Zhao, Hongyu Zhu, Yang Li, Kanghong Zhou, Wei Ge, Jianyuan Hao. Improved synthesis of graphene oxide with controlled oxidation degree by using different dihydrogen phosphate as intercalators. Chemical Physics 2020, 539 , 110938. https://doi.org/10.1016/j.chemphys.2020.110938
  96. Wongi Jang, Jaehan Yun, Yejun Park, In Kee Park, Hongsik Byun, Chang Hyun Lee. Polyacrylonitrile Nanofiber Membrane Modified with Ag/GO Composite for Water Purification System. Polymers 2020, 12 (11) , 2441. https://doi.org/10.3390/polym12112441
  97. R. Perez-Gonzalez, S. Cherepanov, V. Rodriguez-Gonzalez, A.I. Mtz-Enriquez, K.P. Padmasree, A. Zakhidov, J. Oliva. Using Ca2.9Nd0.1Co4O9+δ perovskites to convert a flexible carbon nanotube based supercapacitor to a battery-like device. Electrochimica Acta 2020, 355 , 136768. https://doi.org/10.1016/j.electacta.2020.136768
  98. Rabia Ikram, Badrul Mohamed Jan, Waqas Ahmad. An overview of industrial scalable production of graphene oxide and analytical approaches for synthesis and characterization. Journal of Materials Research and Technology 2020, 9 (5) , 11587-11610. https://doi.org/10.1016/j.jmrt.2020.08.050
  99. Ishita Matai, Gurvinder Kaur, Sanjeev Soni, Abhay Sachdev, Vikas, Sunita Mishra. Near-infrared stimulated hydrogel patch for photothermal therapeutics and thermoresponsive drug delivery. Journal of Photochemistry and Photobiology B: Biology 2020, 210 , 111960. https://doi.org/10.1016/j.jphotobiol.2020.111960
  100. Issam Boukhoubza, Mohammed Khenfouch, Mohamed Achehboune, Liviu Leontie, Aurelian Catalin Galca, Monica Enculescu, Aurelian Carlescu, Mohammed Guerboub, Bakang Moses Mothudi, Anouar Jorio, Izeddine Zorkani. Graphene Oxide Concentration Effect on the Optoelectronic Properties of ZnO/GO Nanocomposites. Nanomaterials 2020, 10 (8) , 1532. https://doi.org/10.3390/nano10081532
Load all citations
  • Abstract

    Figure 1

    Figure 1. XRD patterns of (a) graphite electrode and exfoliated graphite and (b) different GO batches.

    Figure 2

    Figure 2. Calculated crystallite sizes from Raman and XRD data, and the ID/IG area ratio for GO samples with varying oxidation times and Marcano’s method.

    Figure 3

    Figure 3. (a) FTIR plots for GO batches; (b, c) normalized FTIR plot; and (d) RPOCFG profile for GO samples with varying oxidation times and Marcano’s method (M).

    Figure 4

    Figure 4. (a) XPS (a) C 1s and (b) O 1s spectra of GO (6 h).

    Figure 5

    Figure 5. Concentrations of various functional groups in GO samples with varying oxidation times and Marcano’s method.

    Figure 6

    Figure 6. UV–visible spectra of different GO batches.

    Figure 7

    Figure 7. FE-SEM images of GO corresponding to reaction times of (a) GO (1 h), (b) GO (2 h), (c) GO (4 h), (d) GO (6 h), (e) GO (8 h), (f) GO (10 h), and (g) GO (12 h); (h, i) TEM images of GO (6 h); and (j) SAED pattern of GO (6 h).

    Figure 8

    Figure 8. TG profiles of different GO batches.

    Figure 9

    Figure 9. Graphical representation of the synthesis of graphene oxide using electrochemical exfoliation coupled with oxidation.

    Figure 10

    Figure 10. Representation of various steps involved in the synthesis of graphene oxide.

  • References

    ARTICLE SECTIONS
    Jump To

    This article references 61 other publications.

    1. 1
      Allen, M. J.; Tung, V. C.; B, K. R. Honeycomb Carbon A Study of Graphene. Chem. Rev. 2010, 110, 132145,  DOI: 10.1021/cr900070d
    2. 2
      Chen, D.; Feng, H.; Li, J. Graphene Oxide: Preparation, Functionalization, and Electrochemical Applications. Chem. Rev. 2012, 112, 60276053,  DOI: 10.1021/cr300115g
    3. 3
      Natarajan, J.; Madras, G.; Chatterjee, K. Development of Graphene Oxide-/Galactitol Polyester-Based Biodegradable Composites for Biomedical Applications. ACS Omega 2017, 2, 55455556,  DOI: 10.1021/acsomega.7b01139
    4. 4
      Bjerglund, E. T.; Kristensen, M. E. P.; Stambula, S.; Botton, G. A.; Pedersen, S. U.; Daasbjerg, K. Efficient Graphene Production by Combined Bipolar Electrochemical Intercalation and High-Shear Exfoliation. ACS Omega 2017, 2, 64926499,  DOI: 10.1021/acsomega.7b01057
    5. 5
      Gleason, K.; Saraf, S.; Seal, S.; Putnam, S. A. Atmospheric Deposition of Modified Graphene Oxide on Silicon by Evaporation-Assisted Deposition. ACS Omega 2018, 3, 11541158,  DOI: 10.1021/acsomega.7b01816
    6. 6
      Balandin, A. A.; Ghosh, S.; Bao, W.; Calizo, I.; Teweldebrhan, D.; Miao, F.; Lau, C. N. Superior Thermal Conductivity of Single-Layer Graphene. Nano Lett. 2008, 8, 902907,  DOI: 10.1021/nl0731872
    7. 7
      Lee, C.; Wei, X.; Kysar, J. W.; Hone, J. Measurements of the Elastic Properties and Intrinsic Strength of Monolayer Graphene. Science 2008, 321, 385388,  DOI: 10.1126/science.1157996
    8. 8
      Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L. Ultrahigh Electron Mobility in Suspended Graphene. Solid State Commun. 2008, 146, 351355,  DOI: 10.1016/j.ssc.2008.02.024
    9. 9
      Choi, W.; Lahiri, I.; Seelaboyina, R.; Kang, Y. S. Synthesis of Graphene and Its Applications: A Review. Crit. Rev. Solid State Mater. Sci. 2010, 35, 5271,  DOI: 10.1080/10408430903505036
    10. 10
      Novoselov, K. S.; Fal’ko, V. I.; Colombo, L.; Gellert, P. R.; Schwab, M. G.; Kim, K. A Roadmap for Graphene. Nature 2012, 490, 192200,  DOI: 10.1038/nature11458
    11. 11
      Wang, Y.; Li, Z.; Wang, J.; Li, J.; Lin, Y. Graphene and Graphene Oxide: Biofunctionalization and Applications in Biotechnology. Trends Biotechnol. 2011, 29, 205212,  DOI: 10.1016/j.tibtech.2011.01.008
    12. 12
      Pumera, M. Graphene-Based Nanomaterials for Energy Storage. Energy Environ. Sci. 2011, 4, 668,  DOI: 10.1039/C0EE00295J
    13. 13
      Brownson, D. A. C.; Kampouris, D. K.; Banks, C. E. An Overview of Graphene in Energy Production and Storage Applications. J. Power Sources 2011, 196, 48734885,  DOI: 10.1016/j.jpowsour.2011.02.022
    14. 14
      Kemp, K. C.; Seema, H.; Saleh, M.; Le, N. H.; Mahesh, K.; Chandra, V.; Kim, K. S. Environmental Applications Using Graphene Composites: Water Remediation and Gas Adsorption. Nanoscale 2013, 5, 31493171,  DOI: 10.1039/c3nr33708a
    15. 15
      Hummers, W. S.; Offeman, R. E. Preparation of Graphitic Oxide. J. Am. Chem. Soc. 1958, 80, 1339,  DOI: 10.1021/ja01539a017
    16. 16
      Chen, J.; Yao, B.; Li, C.; Shi, G. An Improved Hummers Method for Eco-Friendly Synthesis of Graphene Oxide. Carbon 2013, 64, 225229,  DOI: 10.1016/j.carbon.2013.07.055
    17. 17
      Chen, J.; Li, Y.; Huang, L.; Li, C.; Shi, G. High-Yield Preparation of Graphene Oxide from Small Graphite Flakes via an Improved Hummers Method with a Simple Purification Process. Carbon 2015, 81, 826834,  DOI: 10.1016/j.carbon.2014.10.033
    18. 18
      Kovtyukhova, N. I.; Ollivier, P. J.; Martin, B. R.; Mallouk, T. E.; Chizhik, S. A.; Buzaneva, E. V.; Gorchinskiy, A. D. Layer-by-Layer Assembly of Ultrathin Composite Films from Micron-Sized Graphite Oxide Sheets and Polycations. Chem. Mater. 1999, 11, 771778,  DOI: 10.1021/cm981085u
    19. 19
      Sun, J.; Yang, N.; Sun, Z.; Zeng, M.; Fu, L.; Hu, C.; Hu, S. Fully Converting Graphite into Graphene Oxide Hydrogels by Preoxidation with Impure Manganese Dioxide. ACS Appl. Mater. Interfaces 2015, 7, 2135621363,  DOI: 10.1021/acsami.5b06008
    20. 20
      Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z.; Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. Improved Synthesis of Graphene Oxide. ACS Nano 2010, 4, 48064814,  DOI: 10.1021/nn1006368
    21. 21
      Liou, Y. J.; Tsai, B. D.; Huang, W. J. An Economic Route to Mass Production of Graphene Oxide Solution for Preparing Graphene Oxide Papers. Mater. Sci., Eng. B 2015, 193, 3740,  DOI: 10.1016/j.mseb.2014.11.007
    22. 22
      Hu, Y.; Song, S.; Lopez-Valdivieso, A. Effects of Oxidation on the Defect of Reduced Graphene Oxides in Graphene Preparation. J. Colloid Interface Sci. 2015, 450, 6873,  DOI: 10.1016/j.jcis.2015.02.059
    23. 23
      Shahriary, L.; Athawale, A. A. Graphene Oxide Synthesized by Using Modified Hummers Approach. Int. J. Renew. Energy Environ. Eng. 2014, 02, 5863
    24. 24
      Wang, G.; Yang, J.; Park, J.; Gou, X.; Wang, B.; Liu, H.; Yao, J. Facile Synthesis and Characterization of Graphene Nanosheets. J. Phys. Chem. C 2008, 112, 81928195,  DOI: 10.1021/jp710931h
    25. 25
      Li, C.; Xu, Y. T.; Zhao, B.; Jiang, L.; Chen, S. G.; Xu, J. B.; Fu, X. Z.; Sun, R.; Wong, C. P. Flexible Graphene Electrothermal Films Made from Electrochemically Exfoliated Graphite. J. Mater. Sci. 2016, 51, 10431051,  DOI: 10.1007/s10853-015-9434-x
    26. 26
      Punith Kumar, M. K.; Nidhi, M.; Srivastava, C. Electrochemical Exfoliation of Graphite to Produce Graphene Using Tetrasodium Pyrophosphate. RSC Adv. 2015, 5, 2484624852,  DOI: 10.1039/C5RA01304F
    27. 27
      Kakaei, K.; Hasanpour, K. Synthesis of Graphene Oxide Nanosheets by Electrochemical Exfoliation of Graphite in Cetyltrimethylammonium Bromide and Its Application for Oxygen Reduction. J. Mater. Chem. A 2014, 2, 15428,  DOI: 10.1039/C4TA03026E
    28. 28
      Rao, K. S.; Senthilnathan, J.; Liu, Y.-F.; Yoshimura, M. Role of Peroxide Ions in Formation of Graphene Nanosheets by Electrochemical Exfoliation of Graphite. Sci. Rep. 2014, 4, 4237  DOI: 10.1038/srep04237
    29. 29
      Parvez, K.; Li, R.; Puniredd, S. R.; Hernandez, Y.; Hinkel, F.; Wang, S.; Feng, X.; Mullen, K. Electrochemically Exfoliated Graphene as Solution-Processable, Highly Conductive Electrodes for Organic Electronics. ACS Nano 2013, 7, 35983606,  DOI: 10.1021/nn400576v
    30. 30
      Su, C. Y.; Lu, A. Y.; Xu, Y.; Chen, F. R.; Khlobystov, A. N.; Li, L. J. High-Quality Thin Graphene Films from Fast Electrochemical Exfoliation. ACS Nano 2011, 5, 23322339,  DOI: 10.1021/nn200025p
    31. 31
      Mao, M.; Wang, M.; Hu, J.; Lei, G.; Chen, S.; Liu, H. Simultaneous Electrochemical Synthesis of Few-Layer Graphene Flakes on Both Electrodes in Protic Ionic Liquids. Chem. Commun. 2013, 49, 5301,  DOI: 10.1039/c3cc41909f
    32. 32
      Brodie, B. C. On the Atomic Weight of Graphite. Philos. Trans. R. Soc. London 1859, 149, 249259,  DOI: 10.1098/rstl.1859.0013
    33. 33
      Staudenmaier, L. Verfahren Zur Darstellung Der Graphitsure. Ber. Dtsch. Chem. Ges. 1898, 31, 14811487,  DOI: 10.1002/cber.18980310237
    34. 34
      Kaur, M.; Kaur, H.; Kukkar, D. Synthesis and Characterization of Graphene Oxide Using Modified Hummer ’ s Method. AIP Conf. Proc. 2018, 030180  DOI: 10.1063/1.5032515
    35. 35
      Singh, S. K.; Singh, M. K.; Kulkarni, P. P.; Sonkar, V. K.; Grácio, J. J. A.; Dash, D. Amine-Modified Graphene: Thrombo-Protective Safer Alternative to Graphene Oxide for Biomedical Applications. ACS Nano 2012, 6, 27312740,  DOI: 10.1021/nn300172t
    36. 36
      Kaladevi, G.; Meenakshi, S.; Pandian, K.; Wilson, P. Synthesis of Well-Dispersed Silver Nanoparticles on Polypyrrole/Reduced Graphene Oxide Nanocomposite for Simultaneous Detection of Toxic Hydrazine and Nitrite in Water Sources. J. Electrochem. Soc. 2017, 164, B620B631,  DOI: 10.1149/2.0611713jes
    37. 37
      López-Díaz, D.; Lopez Holgado, M.; Garcia-Fierro, J. L.; Velazquez, M. M. Evolution of the Raman Spectrum with the Chemical Composition of Graphene Oxide. J. Phys. Chem. C 2017, 121, 2048920497,  DOI: 10.1021/acs.jpcc.7b06236
    38. 38
      Mehta, J. S.; Faucett, A. C.; Sharma, A.; Mativetsky, J. M. How Reliable Are Raman Spectroscopy Measurements of Graphene Oxide. J. Phys. Chem. C 2017, 121, 1658416591,  DOI: 10.1021/acs.jpcc.7b04517
    39. 39
      Tandel, R. D.; Pawar, S. K.; Seetharamappa, J. Synthesis and Characterization of Bentonite-Reduced Graphene Oxide Composite: Application as Sensor for a Neurotransmitter, Dopamine. J. Electrochem. Soc. 2016, 163, H705H713,  DOI: 10.1149/2.0991608jes
    40. 40
      Verma, S.; Dutta, R. K. Development of Cysteine Amide Reduced Graphene Oxide (CARGO) Nano-Adsorbents for Enhanced Uranyl Ions Removal from Aqueous Medium. J. Environ. Chem. Eng. 2017, 5, 45474558,  DOI: 10.1016/j.jece.2017.08.047
    41. 41
      Cançado, L. G.; Gomes-da-Silva, M.; Ferreira, E. H. M.; Hof, F.; Kampioti, K.; Huang, K.; Penicaud, A.; Achete, C. A.; Capaz, R. B.; Jorio, A. Disentangling contributions of point and line defects in the Raman spectra of graphene-related materials. 2D Mater. 2017, 4, 025039  DOI: 10.1088/2053-1583/aa5e77
    42. 42
      Tuinstra, F.; Koenig, J. L. Raman Spectrum of Graphite. J. Chem. Phys. 1970, 53, 11261130,  DOI: 10.1063/1.1674108
    43. 43
      Guerrero-Contreras, J.; Caballero-Briones, F. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method. Mater. Chem. Phys. 2015, 153, 209220,  DOI: 10.1016/j.matchemphys.2015.01.005
    44. 44
      Kudin, K. N.; Ozbas, B.; Schniepp, H. C.; Prud, R. K.; Aksay, I. A.; Car, R.; Prud’Homme, R. K. Raman Spectra of Graphite Oxide and Functionalized Graphene Sheets. Nano Lett. 2008, 8, 3641,  DOI: 10.1021/nl071822y
    45. 45
      Minitha, C. R.; Anithaa, V. S.; Subramaniam, V.; Rajendra Kumar, R. T. Impact of Oxygen Functional Groups on Reduced Graphene Oxide-Based Sensors for Ammonia and Toluene Detection at Room Temperature. ACS Omega 2018, 3, 41054112,  DOI: 10.1021/acsomega.7b02085
    46. 46
      Paredes, J. I.; Marti, A.; Tasco, J. M. D.; Martı, A. Graphene Oxide Dispersions in Organic Solvents Graphene Oxide Dispersions in Organic Solvents. Langmuir 2008, 24, 1056010564,  DOI: 10.1021/la801744a
    47. 47
      Verma, S.; Dutta, R. K. A Facile Method of Synthesizing Ammonia Modified Graphene Oxide for Efficient Removal of Uranyl Ions from Aqueous Medium. RSC Adv. 2015, 5, 7719277203,  DOI: 10.1039/C5RA10555B
    48. 48
      Yang, Z.; Zheng, X.; Zheng, J. A Facile One-Step Synthesis of Fe2O3 Nanoparticles/Reduced Graphene Oxide for Enhanced Hydrazine Sensing. J. Electrochem. Soc. 2017, 164, B74B80,  DOI: 10.1149/2.0031704jes
    49. 49
      Wei, Y.; Jang, C. H. Liquid Crystal as Sensing Platforms for Determining the Effect of Graphene Oxide-Based Materials on Phospholipid Membranes and Monitoring Antibacterial Activity. Sens. Actuators, B 2018, 254, 7280,  DOI: 10.1016/j.snb.2017.07.057
    50. 50
      Pei, S.; Wei, Q.; Huang, K.; Cheng, H. M.; Ren, W. Green Synthesis of Graphene Oxide by Seconds Timescale Water Electrolytic Oxidation. Nat. Commun. 2018, 9, 145  DOI: 10.1038/s41467-017-02479-z
    51. 51
      Ahirwar, S.; Mallick, S.; Bahadur, D. Electrochemical Method to Prepare Graphene Quantum Dots and Graphene Oxide Quantum Dots. ACS Omega 2017, 2, 83438353,  DOI: 10.1021/acsomega.7b01539
    52. 52
      Shao, G.; Lu, Y.; Wu, F.; Yang, C.; Zeng, F.; Wu, Q. Graphene Oxide: The Mechanisms of Oxidation and Exfoliation. J. Mater. Sci. 2012, 47, 44004409,  DOI: 10.1007/s10853-012-6294-5
    53. 53
      Gupta, T. K.; Singh, B. P.; Tripathi, R. K.; Dhakate, S. R.; Singh, V. N.; Panwar, O. S.; Mathur, R. B. Superior Nano-Mechanical Properties of Reduced Graphene Oxide Reinforced Polyurethane Composites. RSC Adv. 2015, 5, 1692116930,  DOI: 10.1039/C4RA14223C
    54. 54
      Huang, N. M.; Lim, H. N.; Chia, C. H.; Yarmo, M. A.; Muhamad, M. R. Simple Room-temperature Preparation of High-yield Large-area Graphene oxide. Int. J. Nanomed. 2011, 6, 34433448,  DOI: 10.2147/IJN.S26812
    55. 55
      Lai, Q.; Zhu, S.; Luo, X.; Zou, M.; Huang, S. Ultraviolet-Visible Spectroscopy of Graphene Oxides. AIP Adv. 2012, 2, 032146  DOI: 10.1063/1.4747817
    56. 56
      Dong, L.; Yang, J.; Chhowalla, M.; Loh, K. P. Synthesis and Reduction of Large Sized Graphene Oxide Sheets. Chem. Soc. Rev. 2017, 46, 73067316,  DOI: 10.1039/C7CS00485K
    57. 57
      Wilson, N. R.; Pandey, P. A.; Beanland, R.; Young, R. J.; Kinloch, I. A.; Gong, L.; Liu, Z.; Suenaga, K.; Rourke, J. P.; York, S. J.; Sloan, J. Graphene Oxide: Structural Analysis and Application as a Highly Transparent Support for Electron Microscopy. ACS Nano 2009, 3, 25472556,  DOI: 10.1021/nn900694t
    58. 58
      Mkhoyan, K. A.; Contryman, A. W.; Silcox, J.; Stewart, D. A.; Eda; Mattevi, C.; Miller, S.; Chhowalla, M. Atomic and Electronic Structure of Graphene-Oxide. Nano Lett. 2009, 9, 10581063,  DOI: 10.1021/nl8034256
    59. 59
      Krishnamoorthy, K.; Veerapandian, M.; Yun, K.; Kim, S.-J. The Chemical and Structural Analysis of Graphene Oxide with Different Degrees of Oxidation. Carbon 2013, 53, 3849,  DOI: 10.1016/j.carbon.2012.10.013
    60. 60
      Dreyer, D. R.; Park, S.; Bielawski, C. W.; Ruoff, R. S. The Chemistry of Graphene Oxide. Chem. Soc. Rev. 2010, 39, 228240,  DOI: 10.1039/B917103G
    61. 61
      Dimiev, A. M.; Tour, J. M. Mechanism of Graphene Oxide Formation. ACS Nano 2014, 8, 30603068,  DOI: 10.1021/nn500606a
  • Supporting Information

    Supporting Information

    ARTICLE SECTIONS
    Jump To

    The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsomega.8b01283.

    • Raman spectra of different GO batches and deconvoluted FTIR graphs in the wavenumber range of 1500–18500 cm–1 (PDF)


    Terms & Conditions

    Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

Pair your accounts.

Export articles to Mendeley

Get article recommendations from ACS based on references in your Mendeley library.

You’ve supercharged your research process with ACS and Mendeley!

STEP 1:
Click to create an ACS ID

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

MENDELEY PAIRING EXPIRED
Your Mendeley pairing has expired. Please reconnect