Meeting the Clean Energy Demand:  Nanostructure Architectures for Solar Energy Conversion

Prashant V. Kamat is currently a Professor of Chemistry and Biochemistry, a Senior Scientist at Radiation Laboratory, and a Concurrent Professor in the Department of Chemical and Biomolecular Engineering, University of Notre Dame. A native of Binaga, India, he earned his masters (1974) and doctoral degrees (1979) in Physical Chemistry from the Bombay University, and carried out his postdoctoral research at Boston University (1979−1981) and University of Texas at Austin (1981−1983). He joined Notre Dame Radiation Laboratory in 1983 and initiated the photoelectrochemical investigation of semiconductor nanoparticles. Dr. Kamat's research has made significant contributions to three areas :  (1) photoinduced catalytic reactions using semiconductor and metal nanoparticles, nanostructures and nanocomposites, (2) advanced materials such as inorganic−organic hybrid assemblies for utilizing renewable energy resources, and (3) environmental remediation using advanced oxidation processes and chemical sensors. He has directed DOE funded solar photochemistry research for more than 20 years. He has published more than 300 peer-reviewed journal papers, review articles, and book chapters. He has edited two books in the area of nanoscale materials. He was a fellow of Japan Society for Promotion of Science during 1997 and 2003 and was presented the 2006 Honda-Fujishima Lectureship award by the Japan Photochemical Society.

The increasing energy demand in the near future will force us to seek environmentally clean alternative energy resources. The emergence of nanomaterials as the new building blocks to construct light energy harvesting assemblies has opened up new ways to utilize renewable energy sources. This article discusses three major ways to utilize nanostructures for the design of solar energy conversion devices:  (i) Mimicking photosynthesis with donor−acceptor molecular assemblies or clusters, (ii) semiconductor assisted photocatalysis to produce fuels such as hydrogen, and (iii) nanostructure semiconductor based solar cells. This account further highlights some of the recent developments in these areas and points out the factors that limit the efficiency optimization. Strategies to employ ordered assemblies of semiconductor and metal nanoparticles, inorganic-organic hybrid assemblies, and carbon nanostructures in the energy conversion schemes are also discussed. Directing the future research efforts toward utilization of such tailored nanostructures or ordered hybrid assemblies will play an important task in achieving the desired goal of cheap and efficient fuel production (e.g., solar hydrogen production) or electricity (photochemical solar cells).