Photoelectrochemical cells are a promising approach for converting solar energy to storable chemical energy in chemical fuels. The efficiency of these devices depends critically on efficient transfer of charge carrier across the electrode liquid interface and the efficiency and selectivity of the catalytic reaction on electrode surface. Although transient absorption spectroscopy is a powerful tool for probing interfacial dynamics in high surface area electrodes, it is often not applicable on planar electrodes because the observed signal is often dominated by carrier dynamics in the bulk. In this talk, we discuss our recent effort in developing <i>in situ </i>time-resolved linear and nonlinear spectroscopic tools that can be used to probe carrier dynamics and reactions at planar electrode/liquid interfaces. Using electric field induced second harmonic generation (EFISH) spectroscopy, we demonstrated in-situ probe of photoinduced change of built-in electric field of a single-crystal rutile TiO2 photoanode under water oxidation reaction process. Using vibrational sum frequency generation spectroscopy, we directly probe the molecular catalysts adsorbed on single-crystal rutile TiO2 electrodes under catalytic reaction conditions. We will discuss how these spectroscopy methods provide detailed insight on dynamics of photogenerated charge carrier and catalysts under photoelectrochemical conditions.

<i>In situ</i> nonlinear spectroscopic probe of charge carrier dynamics and molecular catalysts at semiconductor photoelectrode liquid interface

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

In situ nonlinear spectroscopic probe of charge carrier dynamics and molecular catalysts at semiconductor photoelectrode liquid interface