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.