The enhancement of photocatalytic CO2 reduction by the in situ growth of TiO2 on Ti3C2 MXene

Abstract

The photocatalytic reduction of CO₂ to solar fuel can solve energy crisis and global warming problems. Herein, TiO₂/Ti₃C₂ was prepared via an improved sol–gel method and applied for the photocatalytic reduction of CO₂. TEM, Raman, XPS, and other characterization results proved that TiO₂ was grown in situ on Ti₃C₂ and formed a Schottky junction in the TiO₂/Ti₃C₂ composite. The production rates of CO and CH₄ for the optimal TiO₂/Ti₃C₂ were 2.8 and 4.0 times higher than that of TiO₂, respectively. The enhanced photocatalytic performance was due to the intimate interface between TiO₂ and Ti₃C₂ with the formation of a Schottky junction, which promoted the separation of electron–hole pairs. The effect of the adsorption of TEOA on the photocatalytic performance was studied. Also, the mechanism for the photocatalytic reduction of CO₂ in the TiO₂/Ti₃C₂ system was proposed. This study shows that the intimate interface formed via the in situ growth of TiO₂ on Ti₃C₂ is beneficial for the photocatalytic reduction of CO₂.