CVD Assisted Synthesis of Macro/Mesoporous TiO₂/g‐C₃N₄ S‐Scheme Heterojunction for Enhanced Photocatalytic Hydrogen Evolution

Abstract Photocatalytic H₂ evolution is regarded as an ideal approach to produce green energy. Here, a step‐scheme (S‐scheme) heterojunction of macro/mesoporous TiO₂/g‐C₃N₄ photocatalysts with enhanced H₂ evolution performance is constructed via a simple chemical vapor deposition process. It is found that the microstructure of samples can be easily controlled by adjusting the dosage of melamine. As compared to the respective monocomponent TiO₂ and g‐C₃N₄, the H₂ evolution rate of TiO₂/g‐C₃N₄ S‐scheme heterojunction is greatly improved. The H₂ evolution rate of the 20CT sample reaches the maximum value of 3211 μmol g⁻¹ h⁻¹, which is much higher than those of TiO₂ and g‐C₃N₄ by factors of 27.2 and 7.5, respectively. In addition, through in‐depth analysis with photoluminescence, X‐ray photoelectron spectroscopy, and Mott–Schottky characterizations, a new mechanism of S‐scheme heterojunction is proposed for the obtained system. The formation of the S‐scheme heterojunction in TiO₂/g‐C₃N₄ is therefore responsible for the observed photocatalytic performance enhancement, due to the efficient charge separation as well as the high redox ability.