Recent advances in coupling pollutants degradation with hydrogen production by semiconductor photocatalysis

Coupling pollutants degradation with hydrogen production (CPDWHP) by semiconductor photocatalysis technique provides a significant approach to tackle with the environmental and energy challenges we are currently facing. This technology capitalizes on two crucial half-reactions of the photocatalytic oxidation-reduction process. It is of significance to design suitable semiconductor catalysts and composite materials according to different pollutant systems. This review introduces and categorizes recent breakthroughs and advancements in CPDWHP. Firstly, it outlines the fundamental principles of this technology. Subsequently, it categorizes and summarizes various pollutants, highlighting the progress of coupled photocatalysis and emphasizing different pollutant types, degradation pathways in photocatalysis, and the activity of simultaneous hydrogen production. Furthermore, it summarizes the effects of crystal facets, surface wettability, crystallinity, and co-catalytic effects in composite catalytic systems, as well as the enhancement of catalytic activity by single and multiple heterojunctions. Finally, the challenges and solutions facing CPDWHP are looked forward, including emerging pollutant types and corresponding photocatalyst design, charge separation regulation in CPDWHP system, precise control of photocatalytic pollutant degradation and the selection of reduction process corresponding to hydrogen production, and the influence of element content on the system.