Construction of 0D Ti3C2O2/2D black phosphorus S-scheme heterostructure for photocatalytic CO2 reduction

Photocatalytic carbon dioxide reduction reactions (CO2RR) have aroused great interest in the field of carbon neutrality and clean energy production. CH4 is an ideal product of CO2RR as a clean -burning fuel and the major component of natural gas. However, the efficient separation of photogenerated carriers and the effective activation of CO2 molecules are critical issues of CO2 reduction catalysts. Based on density functional theory, we investigated the catalytic performance for the 0D/2D heterostructure composed of Ti3C2O2 quantum dots (T3QD) and black phosphorene (BP). The contact between the two components in 0D/2D heterostructure induced a builtin electric field and caused band bending, forming an S -scheme transfer mechanism that facilitated efficient charge separation while maintaining a high reactive potential. The edge site of T3QD has excellent catalytic activity to activate CO2 molecules and form key intermediates for eventual reduction to CH4. This work provides theoretical guidance for designing 0D MXene and constructing 0D/2D heterojunctions for photocatalytic applications.