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.