Surface-Plasmon Enhanced Photocatalytic Activity of Metal/Semiconductor Composites for Solar Fuel Production

West Virginia University Research Corporation, Morgantown WV

Investigators

Abstract

PI: Wu, Nianqiang Proposal Number: 1233795 Institution: West Virginia University Research Corporation Title: Surface-Plasmon Enhanced Photocatalytic Activity of Metal/Semiconductor Composites for Solar Fuel Production Solar energy can convert water and carbon dioxide into fuel using semiconductor photocatalysts. Current photocatalysts have a very low solar-to-chemical energy efficiency due to insufficient charge separation and high recombination rates, which has hindered their commercialization. Incorporating plasmonic metal nanostructures with semiconductor photocatalysts offers a new route to enhance the photocatalytic activity toward efficient solar-to-chemical energy conversion by using localized surface plasmon resonances. The project objective is to understand the mechanisms of surface-plasmon-enhanced photocatalysis in metal/semiconductor composite nanostructures. In particular, it is hypothesized that resonant energy transfer from the plasmonic metal (i.e., energy donor) to the semiconductor (i.e., energy acceptor) can induce electron-hole pairs in the semiconductor, leading to enhancement in photocatalysis. In the proposed work, different metal/semiconductor composite nanostructures will be designed and synthesized to (i) separate localized surface plasmon resonance effects from surface catalysis effect of metals, and (ii) distinguish resonant energy transfer and direct electron transfer processes. The correlation of photocatalytic water-splitting activity with the composition and geometry of metal/semiconductor nanoparticles will be studied. In particular, the photocatalytic water-splitting activity of metal/semiconductor composites will be measured as a function of illumination wavelength. Effects of localized surface plasmon resonances on charge separation, migration and recombination will be studied by combining photocatalysis and transient absorption spectroscopy with finite-difference time-domain simulation. The results from the project have potential to improve solar-to-chemical energy conversion efficiency of photocatalysts for solar fuel production, and to develop new materials and architectures for photovoltaic and sensing devices. The proposed research will facilitate the utilization of solar energy for a sustainable energy future. The project will train graduate and undergraduate students, including those from the underrepresented group, during the research program. Students will receive a well-rounded training in an interdisciplinary research environment at the intersection of energy science, nanomaterials, physical chemistry and optical physics. The proposed research will also offer an opportunity for high school teachers to work on cutting-edge research technology and to transfer knowledge back to their classrooms. In addition, the results obtained will be used as the modules of higher education courses in energy science and engineering.