A surface-alkalinized Ti3C2 MXene as an efficient cocatalyst for enhanced photocatalytic CO2 reduction over ZnO?

Catalysis Science & Technology Pub Date: 2021-06-07 DOI: 10.1039/D1CY00716E

Abstract

Photocatalytic reduction of carbon dioxide (CO2) into hydrocarbon fuels has attracted increasing research attention in recent years. However, the fast recombination of photoinduced charge carriers and poor adsorption/activation capability of CO2 molecules limit the photoconversion efficiency. Herein, we report on loading a two-dimensional (2D) titanium carbide (Ti3C2) MXene as a noble-metal-free cocatalyst onto zinc oxide (ZnO) via a facile electrostatic self-assembly method for efficient CO2 photoreduction. It is interesting to find that the ZnO loaded with 7.5 wt% of surface-alkalinized Ti3C2 exhibited remarkably improved evolution rates of CO (30.30 μmol g?1 h?1) and CH4 (20.33 μmol g?1 h?1), which were approximately 7-fold and 35-fold those of bare ZnO, respectively. The surface-alkalinized Ti3C2 MXene is believed to play a crucial role in improving the separation/transfer of photoinduced charge carriers and the adsorption/activation of CO2 molecules, accounting for the superior photocatalytic activity of CO2 reduction. Our work demonstrates that the Ti3C2 MXene could be employed as a noble-metal-free cocatalyst for efficient photocatalytic CO2 reduction.

Graphical abstract: A surface-alkalinized Ti3C2 MXene as an efficient cocatalyst for enhanced photocatalytic CO2 reduction over ZnO
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