Achieving Visible Light Triggered Overall Water Splitting over Plasmonic Au/SrTiO3:Al Photocatalyst

Abstract

The surface plasmon resonance (SPR) effect has garnered extensive attention in semiconductor photocatalysis for solar energy conversion, thanks to its remarkable optical properties. However, the majority SPR-induced photocatalytic systems have been limited to achieving hydrogen evolution or oxygen evolution half reactions, and attaining overall water splitting on a SPR-induced photocatalyst under visible light remains a formidable challenging. In this study, we employed a plasmonic photocatalyst Au/SrTiO₃, and further enhanced its performance by doping aluminum (Al) into the SrTiO₃ lattice (denoted as Au/SrTiO₃:Al). By constructing reduction cocatalyst (RhCrO_x) and oxidation cocatalyst (CoOOH), the Au/SrTiO₃:Al photocatalyst successfully realizes photocatalytic overall water splitting with a stoichiometric ratio of H₂ and O₂ under visible light (λ≥440 nm). We revealed that the introduction of Al species effectively modified the electronic structure of SrTiO₃, thereby enhancing the hydrogen evolution reaction in Au/SrTiO₃:Al. Simultaneously, the RhCrO_x and CoOOH cocatalysts synergistically capitalized on the short-lived hot electrons and holes generated by the plasmonic Au/SrTiO₃:Al photocatalyst, enabling to realize photocatalytic overall water splitting. This work offers a promising avenue for the rational design of plasmon-induced overall water splitting photocatalysts through the integration of suitable cocatalysts and surface/interface engineering strategies.