Topic: Solar-Driven Water Splitting
Speaker: Professor Harry Gray - Caltech
Host: Professor Jim McCusker
Date: Wednesday, April 26, 2017
Time: 5:00 PM - 6:00 PM
Location: 138 CEM
Molecular hydrogen has emerged as an attractive candidate for a clean, renewable fuel to meet the world’s skyrocketing demand for energy. Hydrogenase enzymes that contain iron and nickel cofactors evolve H2 catalytically from water with very high turnover frequencies. However, the relative instability of these enzymes under aerobic conditions has led to the search for robust inorganic catalysts for production of hydrogen from water. We are working on heterogeneous inorganic catalysts made from earth-abundant elements that could be part of scalable solar fuel devices. We have found that materials such as Ni–Mo nanopowders and metal phosphide nanocrystals have catalytic efficiencies near that of platinum for reduction of protons in aqueous solutions. A major challenge now is to find scalable materials that can be employed as active catalysts in integrated photoanodes for production of oxygen from water, as required for the generation of protons and electrons for combination at photocathodes. We have found that mixed-metal nanosheet hydroxides made by pulsed laser ablation of precursors in water are very active water oxidation catalysts. We are working on the structures and mechanisms of these nanosheet materials to aid in the design and construction of more efficient and robust integrated photoanodes for water splitting.