Schottky-Barrier-Free Plasmonic WO₃-Based Photocatalysts for Simultaneous N₂ Fixation and H₂O₂ Generation

Plasmonic photocatalysis has recently received much attention in generating high-value-added products. Schottky-barrier-free plasmonic photocatalysts are frontier materials that can effectively employ localized surface plasmon resonance to generate and utilize hot charge carriers. Herein, the development of a new type of Schottky-barrier-free plasmonic WO₃-based photocatalyst through hydrogen doping, oxygen vacancy (OV) introduction, and metal doping is reported. Hydrogen doping and OV introduction broaden the light absorption range of the WO₃-based photocatalyst, thereby enabling the generation of more hot charge carriers. Metal doping provides more catalytically active sites. More interestingly, both hot electrons and holes can be used to generate high-value-added products, i.e., ammonia and hydrogen peroxide. The optimal Mo-H_0.23WO_{3- x} photocatalyst exhibits excellent ammonia and hydrogen peroxide production rates of 187.53 and 196.25 µmol g^-1 h^-1, respectively. Furthermore, a biphasic photocatalytic system is designed to suppress light absorption by water and maximize sunlight utilization. This work expands the scope of plasmonic photocatalysts towards degenerately doped plasmonic metal oxide semiconductors and provides a new paradigm for the solar-driven generation of high-value-added products.