Highly Enhanced Full Solar Spectrum-Driven Photocatalytic CO_2 Reduction Performance in Cu_（2–x）S/g-C_3N_4 Composite: Efficient Charge Transfer and Mechanism Insight

摘要

An efficient full solar spectrum ultraviolet–visible–near infrared (UV–vis–NIR)light-driven Cu2–xS/g-C3N4 composite photocatalyst is reported, which is fabricatedby a facile solvothermal process for CO2 photoreduction into CO and CH4,as confirmed by product analysis and 13C isotopic test. The composite exhibitssuperior full solar-spectrum-driven CO_2 photoreduction performance than pureCu2–xS and g-C3N4, which is attributed to the efficient charge transfer due to theformation of intimate interface contact and S─C bond coupling between Cu2–xSand g-C3N4 based on experimental analyses and theoretical calculations. Inparticular, the activities of the best composite for CO_2 photoreduction into COand CH4 under NIR light irradiation are about 2.6 times and 6.6 times higher thanthat of Cu2–xS, whereas no production is measured over g-C3N4. A possiblemechanism of photocatalytic CO_2 reduction is given based on in situ Fouriertransform infrared (FTIR) analysis. This study paves the way to prepare carbonnitride–based photocatalysts with full-spectrum-responsive property for efficientCO_2 photoreduction.