Tuning W₁₈O₄₉/Cu₂O{111} Interfaces for the Highly Selective CO₂ Photocatalytic Conversion to CH₄

As a multiple proton-coupled electron transfer process, photocatalytic conversion of CO2 usually produces a wide variety of products. Improving the yield and selectivity of CO2 to the single product is still a significant challenge. In this work, we describe that the rationally constructed W18O49/Cu2O{111} interfaces achieve highly selective CO2 photocatalytic conversion to CH4. In situ Fourier transform infrared spectroscopy measurements reveal that the formation of W18O49/Cu2O{111} interfaces restrains the desorption of CO* intermediates in CO2 photocatalytic conversion. UPS spectra, PL spectra, and photocurrent curves show that more photogenerated electrons are excited and transferred to W18O49/Cu2O{111} interfaces. All of these play critical roles in CH4 production. As an outcome, the yield rate of CO2 photocatalytic conversion to CH4 was enhanced from 6.5 to 17.20 μmol g–1 h–1 with selectivity as high as 94.7%. The work demonstrates the feasibility and versatility of interface engineering in achieving highly selective CO2 photocatalytic conversion.