Development of High Surface Area Crystalline Semiconductors for Visible Light Driven Photocatalysis

University Of California-Riverside, Riverside CA

Investigators

Abstract

TECHNICAL SUMMARY: Photocatalytic splitting of water into H2 and O2 using semiconductor-based heterogeneous systems promises to be one of the simplest and most economical methods for solar energy conversion and storage. A major limitation to the practical application of these systems is the lack of stable semiconductor photocatalysts that can carry out the water splitting in the visible region of the solar spectrum with high conversion efficiency. Much of current efforts to improve the efficiency of water photolysis focus on dense bulk semiconductors, and those tend to offer poor conversion efficiency because of their low surface area and significant charge recombination as well as of other problems such as the wide band gaps in oxides and the low photochemical stability of sulfides. Here, through compositional and structural control to achieve band gap engineering, templating approach to enhance surface area and catalytic performance, and systematic photocatalytic and photophysical measurements, we aim to create a family of stable, efficient, and visible light driven nanoporous photocatalysts for water splitting. These photocatalysts will be multi-functional materials that integrate semiconductivity, high crystallinity, and tunable porosity, and will have the potential to overcome the main limitations of known semiconductor photocatalysts. The key advantages offered by these materials include large interfacial surface areas, short electron-hole diffusion lengths to the internal interfaces, and multiple routes for band gap engineering. The proposed project borders on various research areas. It will therefore provide excellent training opportunities for students. NON-TECHNICAL SUMMARY: The proposed research addresses an important energy and environmental issue: the use of renewable and non-polluting energy. It aims to develop new multi-functional materials suitable for energy production and storage such as conversion of renewable solar energy to hydrogen fuel that is environmentally friendly. It will also provide a fundamental understanding about important chemical and structural factors that govern photocatalytic properties and processes. This will allow rational synthetic design and optimization of advanced materials and processes for the hydrogen fuel production. UC Riverside has a very diverse student population with a large enrollment of minority students, and undergraduate research is strongly encouraged at UCR and in the PI?s group. The project combines diversity in materials synthesis and various characterization techniques and provides excellent training opportunities for students. Their research experiences with this project can have a major impact in these students? scientific career in research areas that are of increasing importance to our society.