A Photothermal Mxene-Derived Heterojunction for Boosted Co2 Reduction and Tunable Ch4 Selectivity

Abstract

We report here a Bi2WO6/Ti3C2Tx@Ag (BT@Ag) photothermal photocatalyst for efficient CO2 reduction with tunable CH4 selectivity. Incorporation of Ti3C2Tx MXene creates well-defined heterointerfaces between Bi2WO6 and Ti3C2Tx and converts thermal energy upon light illumination via photothermal effect, which contributes to a mitigation of the recombination of photo-induced charge carries for a high electron mobility. Density functional theory calculations substantiate that Ti3C2Tx functions as the adsorption site and active center where the transferred electrons are effectively involved in CO2 reduction for enhanced CH4 selectivity. Moreover, the in situ deposited Ag nanoparticles demonstrate an exceptional surface plasmon resonance effect, giving rise to additional hot electrons that further benefits the CH4 generation.

Keywords: CO2 reduction, MXene, photocatalysis, Photothermal conversion