Boosting the Photocatalytic Ability of Cu2O Nanowires for CO2 Conversion by MXene Quantum Dots

MXene quantum dots (QDs) are emerging 0D nanomaterials. Here, a new heterostructure is developed based on a 1D photoactive semiconductor and a 0D MXene QD for improved photocatalytic reduction of CO2 into methanol. Specifically, Ti3C2 QDs are incorporated onto Cu2O nanowires (NWs) through a simple self‐assembly strategy. It is demonstrated that Ti3C2 QDs not only significantly improve the stability of Cu2O NWs but also greatly improve their photocatatlytic performance by enhancing charge transfer, charge transport, carrier density, light adsorption, as well as by decreasing band bending edge and charge recombination. The energy level diagram derived from both experimental measurements and theoretical calculations provide further insights of such hierarchical photocatalysis system. Ti3C2 quantum dots greatly enhance the photocatalytic ability of Cu2O nanowires for CO2 conversion by promoting charge transfer, decreasing band bending edge, and increasing carrier density.