J. Phys. Chem. C, 112 (8), 2845 -2850, 2008. 10.1021/jp710190j S1932-7447(71)00190-0
Web Release Date: February 6, 2008

Copyright © 2008 American Chemical Society

Using Elemental Se and Ag to Grow Pure Ag2Se Dendrites/Dendritic-Films of Highly Oriented (001) Nanocrystals

Dapeng Li, Zhi Zheng,* Zhengyang Shui, Mingqiang Long, Jie Yu, Ka Wai Wong, Lin Yang, Lizhi Zhang,* and Woon Ming Lau

Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang, Henan Province 461000, PR China, Department of Physics, The Chinese University of Hong Kong, Shatin, N. T., PR China, College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007, PR China, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China, and Surface Science Western, The University of Western Ontario, London, Ontario, Canada

Received: October 20, 2007

In Final Form: November 27, 2007

Abstract:

A clean, facile route of using only common bulk selenium (Se) powder and silver (Ag) foil in a simple solvothermal process is developed to synthesize a film of silver selenide (Ag2Se) dendrites of highly oriented (001) nanocrystals. The simple process takes ~10 h at 160 C in a common alcohol such as methanol or ethanol in an autoclave, and the reaction time is shorter than in many prevalent methods. The adoption of elemental Se and Ag (foil) in the synthesis eases the control of the purity of the product, simplifies the reaction steps, and reduces the costs, as the synthesis does not require Se and Ag compounds, and also requires no chemical additives other than an alcohol as solvent. The results support a mechanism of dissolution of the bulk-like Se powder in the solvothermal process, transport of solvated Se to react with Ag, nucleation of Ag2Se nanocrystals, surface-mediated, solvation-assisted surface diffusion of Ag2Se nanocrystals, and diffusion-limited aggregation of the Ag2Se nanocrystals through oriented attachment for the growth of dendrites having highly oriented (001) nanocrystals. The clean, relative facile route is practical for the fabrication of Ag2Se crystals/films with hierarchically ordered nanostructures for future applications in solar cell devices. More importantly, the same concept can be adopted for the synthesis of other nanomaterials with bulk elemental reactants with no reliance on chemical compounds or additives.

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