A review on WO3-based composite photocatalysts: synthesis, catalytic mechanism and diversified applications

Photocatalysis as an emerging “green” energy conversion technology has attracted domestic and international attention. This technology uses semiconductor photocatalysts to convert solar energy into directly usable chemical energy, showing great potential for application in environmental pollutant purification and clean energy production, with broad development prospects. Among many semiconductor materials, tungsten trioxide (WO3) is favored by researchers in the field of photocatalysis because of its good visible light response and excellent valence band hole oxidation properties. Currently, a large number of photocatalysts based on WO3, in particular WO3-based composite photocatalysts, have been reported, and their applications cover a wide range of fields. In order to promote the development of WO3-based photocatalysts and provide a reference for colleagues, we present a systematic summary of the applications and research progress of WO3-based composites in the field of photocatalysis in recent years. Starting from the structural properties of WO3 itself, this article summarizes the preparation methods and structure–activity relationships of WO3-based composite photocatalysts. Subsequently, it introduces the current application status of existing WO3-based composite photocatalysts in CO2 reduction, hydrogen production, nitrogen fixation, and pollutant removal. Finally, the development prospects were analyzed.