Integration of Plasmonic Metal and Cocatalyst: An Efficient Strategy for Boosting the Visible and Broad‐Spectrum Photocatalytic H₂ Evolution

Abstract

Abstract The combination of plasmonic metal and cocatalyst with semiconductor has been widely used to simultaneously improve the efficiencies of light absorption, charge separation, and surface reaction for high‐performance photocatalysis. Despite the tremendous efforts, the ternary nanostructures suffer from two bottlenecks: 1) long distance between plasmonic metal and cocatalyst increases the chance of hot electron loss; 2) opposite transmission directions between plasmon‐induced hot electrons and semiconductor‐generated free electrons disfavor the practical application of broad‐spectrum photocatalysis. In this paper, a novel photocatalytic nanostructure, in which plasmonic Au and Pd cocatalysts are integrated into Janus heterojunction on the TiO 2 , is demonstrated. The advantages of the designed photocatalyst include: 1) the shortened distance between Au and Pd as well as the formation of additional channel of Au–Pd interface accelerates the hot electron transfer; 2) the opposite directions of visible‐light‐induced hot electrons and ultraviolet‐light‐excited free electrons are mediated with a unified TiO 2 → Au → Pd transmission route during the broad‐spectrum photocatalysis. As a result, 15 mg of the designed photocatalyst achieves average H 2 production rates of 0.79 and 7.59 µmol h −1 under visible and broad‐spectrum irradiation, respectively, much higher than those of other binary and ternary architectures consisting of TiO 2 , Pd, and Au.