Enhancement of photocatalytic CO2 reduction for novel Cd0.2Zn0.8S@Ti3C2 (MXenes) nanocomposites

Abstract

In order to achieve global energy demand by sustainable energy development and grappling climate change, the ultimate plan is the reduction and conversion of carbon dioxide (CO2). However, in the field of photocatalytic reduction CO2, developing stable, low-cost, and efficient catalyst is still a significant challenge. A series of Cd0.2Zn0.8S@Ti3C2 nanocomposites with different Ti3C2 loading contents are prepared by three-step solvothermal method. Photocatalytic efficiencies of different Cd0.2Zn0.8S@Ti3C2 nanocomposites under visible-light irradiation show that Cd0.2Zn0.8S@Ti3C2 nanocomposite with 5 wt% of Ti3C2 exhibits significant improvement in the photocatalytic performance of CO2 reduction, which shows significant CO (3.31 μmol h−1 g−1) and CH4 (3.51 μmol h−1 g−1) production rates. Such a considerable increase in the photocatalytic efficiency is due to an efficient electron-hole separation and transfer at the interface between Cd0.2Zn0.8S and Ti3C2, which is confirmed by photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). In addition, Cd0.2Zn0.8S@Ti3C2 nanocomposites exhibit high cycling stability during the CO2 photocatalytic reduction, and the photocatalytic mechanism is also discussed.