Highly Selective Conversion of CO2 to C2H6 by Photocatalytic Reduction with NiAl–Layered Double Hydroxides/Bi2Sn2O7–Ov/CuO–Ov Double Oxygen Vacancy Photocatalyst

Abstract

Photocatalytic CO₂ reduction is the use of solar energy to catalyze the conversion of CO₂ into a fuel with added value, and it is an effective way to reuse CO₂ to achieve carbon neutrality. In this study, NiAl–layered double hydroxides (LDH)/Bi₂Sn₂O₇–Ov/CuO–Ov composites with double oxygen vacancies are successfully prepared, and the effects of different component contents are investigated. The main products of the best sample NiAl–LDH/BSOv-40/CuOv-20 are carbon monoxide, methane, and ethane with yields of 29.95, 18.46, and 32.13 μmol g⁻¹ h⁻¹, respectively, and a selectivity of 68.15% for the C₂H₆ product. The evolutionary pathway and photocatalytic mechanism of CO₂ are investigated by in situ Fourier transform infrared spectroscopy and theoretical calculations. In this work, the scope of application of oxygen vacancy catalysts for C₂ production in the field of photocatalysis is broadened.