Enhanced Photocatalytic CO Reduction with Incorporation of WO Cocatalyst in g-CN-TiO Heterojunction.

To enhance the performance of photocatalytic CO reduction, the development of suitable cocatalysts represents an effective strategy. Cocatalysts can interact with photocatalysts to improve light absorption capabilities and facilitate the separation and transfer of photogenerated electrons and holes. Moreover, they provide highly active surface sites that promote the adsorption and activation of CO, which leads to acceleration of photocatalytic reduction. Herein, WO is employed as a cocatalyst to promote the CO photoreduction performance of a g-CN-TiO heterojunction through a facile and scalable calcination method. In pure water, optimal WO/g-CN-TiO (WCT) delivers high selectivity CO and CH formation of 48.31 µmol·g and 77.18 µmol·g in the absence of a sacrificial reagent and extra photosensitizer, roughly 13.9 and 45.7 times higher than that of g-CN-TiO (CT). WO can strongly interact with g-CN-TiO electronically, guiding electrons across the interface to the surface. The oxygen vacancies in WO, as electron-enriched centers, not only enhance charge separation and form efficient charge transfer channels but also capture photogenerated electrons to suppress charge recombination. This strong interaction and oxygen vacancies in WO jointly improve photocatalytic CO reduction activity and selectivity, offering a feasible way to design efficient cocatalysts.