Nanocrystalline Photocatalysts for Hydrogen Production from Splitting of Water by Visible Light

Hydrogen has been widely considered as a clean and renewable energy alternative to coal, natural gas, and other fossil fuels. A potential method for the large-scale production of hydrogen involves the photoelectrochemical splitting of water, using solar energy. Research during the last two decades has shown that metal oxide photocatalysts are effective for overall water splitting; however, most of the metal-oxide photocatalysts developed to date only function in the ultraviolet region, due to their large band gaps (>3 eV). Although a number of photocatalysts driven by visible light have been proposed as potential candidates for this purpose, a satisfactory material has yet to be devised. A successful material would need band edge positions suitable for overall water splitting, a band gap energy smaller than 2.2 eV, and stability in an aqueous solution. This project will prepare nanocrystalline, non-oxide semiconductor materials and evaluate their photoelectrochemical efficiency in the splitting of water using solar energy. In Phase I, a proprietary microwave plasma-assisted synthetic process will be used to synthesize nanopowders. A photoelectrochemical cell will be built for the reliable measurement of the efficiency of the photocatalysts. In Phase II, an efficient photocatalyst will be selected from Phase I results for further development. Commercial Applications and other Benefits as described by the awardee: The nano-photocatalyst should have a wide range of commercial applications, including production of hydrogen for chemical industry, environmental remediation of organic contaminants in water, solar cells, and self-cleaning hydrophilic windows.