Photocatalysis on plasmonic metal nanoparticles/semiconductor heterostructures has garnered people’s attention in the past few decades. Despite many efforts into the investigation of hot-electron photochemistry, the efficient utilization of energetic (or “hot”) holes for photochemical reactions is still desirable. The understanding of hot hole transfer pathways and subsequent structural transformation of the reactants is elusive. Herein, our work demonstrates Au-TiO2-NiOOH multi-component interface effectively prolongs the lifetime of hot holes to drive efficient water oxidation under visible-light illumination. It is discovered that the addition of NiOOH on Au-TiO2 improves the accumulation of photo-generated holes and decreases the charge transfer resistance for water oxidation. This heterostructure boosts water oxidation rate by 2 orders of magnitude compared to that under dark conditions. In-situ Raman spectroscopy results reveal that the NiOOH is oxidized from Ni2+ and Ni3+ species to higher valence Ni4+ states during water oxidation and serves as an ideal hot hole transfer mediator. Our results highlight the novel multi-component metal-semiconductor-cocatalyst interface for hot-hole-driven photocatalysis. This research can be extended to the plasmonic metal-semiconductor-molecule system for understanding the anisotropic hot hole transfer pathways and photocatalytic reaction mechanism.

In-situ study of photo-generated hot hole transfer and photocatalytic water oxidation at plasmonic Au/TiO2/NiOOH interface

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

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