Cuprous ion (Cu) doping induced surface/interface engineering for enhancing the CO photoreduction capability of WO nanowires.

Solar-driven reduction of CO and HO into fuels is a promising approach for addressing global warming and energy crisis. Herein, Cu doped WO nanowires were prepared by a facile solvothermal method and applied in photocatalytic reduction of CO. The composition and structure of pristine and Cu doped WO samples have been characterized. It was found that the morphology of WO nanowires was changed with increasing amounts of dopant. The photocatalytic CO reduction activity of WO nanowires and the Cu doped WO samples were evaluated using HO as reducing agent. The strategy of Cu doping not only could affect the band edge position and the surface wettability, but also influenced separation of the photogenerated electron-hole pairs. It was found that Cu doping could introduce oxygen vacancy and change the conduction edge to a more negative position for WO nanowires, which might be beneficial for the activation of CO and promote the following CO reduction. Furthermore, the higher separation efficiency of photogenerated electron-hole pairs with Cu doping could contribute to the CO photoreduction enhancement. In addition, the Cu doped WO nanowires (Cu-WO-0.005) presented a relatively poor hydrophilic property, which might be beneficial for the adsorption of CO molecules and contribute to its superior photocatalytic CO reduction capability.