Activating two-dimensional Ti3C2Tx-MXene with single-atom cobalt for efficient CO2 photoreduction

Abstract

Summary Artificial CO2 photoreduction to solar fuels represents an eco-friendly and sustainable solution to obtain “sunshine” feedstocks by using renewable energy media. Herein, we report that single cobalt atoms anchored on two-dimensional Ti3C2Tx-MXene nanosheets act as an efficient photocatalytic ensemble for visible-light CO2 reduction, wherein the Ti3C2Tx nanosheets bridge visible-light absorbers (ruthenium complex) with cobalt active sites. The single cobalt atoms build strong interactions with Ti3C2Tx by forming metal-oxygen/carbon bonds, resulting in the formation of the Co-Ti3C2Tx ensemble. As a result, the production rate of CO reaches a high value of 6.06 mmol h−1 g−1 over the optimal Co-Ti3C2Tx, which markedly exceeds previous MXene-based catalysts for CO2 photoreduction. Theoretical calculation manifests that the isolated Co atoms coordinated with Ti3C2Tx can effectively facilitate the generation of CO. This work may provide a new line of thought into the rational design of high-activity MXene-based photocatalysts toward artificial CO2 conversion.