190427 Photoelectrochemical Solar Fuel Production -- Progress and Prospect

Title:
Photoelectrochemical Solar Fuel Production -- Progress and Prospect

Speaker:
姜昌明 (Chang-Ming Jiang), PhD, Technical University of Munich

Time:
04/27 (Sat.) 8 pm PDT, 9 pm MDT, 10 pm CDT, 11 pm EDT
04/28 (Sun.) 11 am Taiwan

Keywords:
Physical chemistry, Semiconductor physics, Photochemistry

Abstract:
Transition metal oxide semiconductors are actively investigated as efficient, durable, and scalable photoelectrodes for direct conversion of solar energy to chemical fuels. However, efficiencies of many newly discovered ternary oxides fall far short of the thermodynamic limits. Optical excitation and carrier transport mechanisms in these open d-shell metal oxide systems are typically complicated by on-site electron correlation. Furthermore, the events governing overall efficiency occur over a broad range of time scales and are affected by a variety of material properties that can be difficult to disentangle in a single compound. Here, a series of copper vanadate photoanodes acts as a platform for analyzing key photoelectrochemical characteristics. As a starting point, we use X-ray and optical spectroscopies to provide a comprehensive portrait of electronic structure. Building on these results, we compare the efficiencies of light absorption, charge separation, and heterogeneous electron transfer as a function of composition. Specific strategies are then identified for improving performance of emerging transition metal oxide photoelectrodes.