Cuprous ion (Cu+) doping induced surface/interface engineering for enhancing the CO2 photoreduction capability of W18O49 nanowires

Solar-driven reduction of CO 2 and H 2 O into fuels is a promising approach for addressing global warming and energy crisis. Herein, Cu + doped W 18 O 49 nanowires were prepared by a facile solvothermal method and applied in photocatalytic reduction of CO 2 . The composition and structure of pristine and Cu + doped W 18 O 49 samples have been characterized. It was found that the morphology of W 18 O 49 nanowires was changed with increasing amounts of dopant . The photocatalytic CO 2 reduction activity of W 18 O 49 nanowires and the Cu + doped W 18 O 49 samples were evaluated using H 2 O 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 W 18 O 49 nanowires, which might be beneficial for the activation of CO 2 and promote the following CO 2 reduction. Furthermore, the higher separation efficiency of photogenerated electron-hole pairs with Cu + doping could contribute to the CO 2 photoreduction enhancement. In addition, the Cu + doped W 18 O 49 nanowires (Cu-W 18 O 49 -0.005) presented a relatively poor hydrophilic property , which might be beneficial for the adsorption of CO 2 molecules and contribute to its superior photocatalytic CO 2 reduction capability.