Multisite-steered C–C coupling for photocatalytic air-concentration CO2 reduction into C2H6

Abstract

Efforts to photoconvert carbon dioxide (CO₂) into C₂ products are primarily hindered by the significant energy barrier of C–C coupling step. Herein, we incorporate active metal particles with localized surface plasmon resonance on metal oxide nanosheets. Also, we construct multiple metal pair sites to boost C–C coupling, thus promoting the formation of C₂ fuels. Taking Au nanoparticles on the Bi₄Ti₃O₁₂ nanosheets as an example, high-resolution transmission electron microscopy images and X-ray photoelectron spectroscopy illuminate the Au-Ti metal pair sites on the Au-Bi₄Ti₃O₁₂ nanosheets. In situ Fourier transform infrared spectra reveal the presence of the *OCCOH intermediate on the surface of Au-Bi₄Ti₃O₁₂ nanosheets during CO₂ photoreduction, while the intermediate is not detected on the Bi₄Ti₃O₁₂ nanosheets. Accordingly, the Au-Bi₄Ti₃O₁₂ nanosheets realize photoreduction of atmospheric-concentration CO₂ into ethane using a single catalyst. By contrast, the Bi₄Ti₃O₁₂ nanosheets alone are limited to producing C₁ products such as carbon monoxide and methane.