Efficient organic–inorganic heterojunction structure for enhancing the photocatalytic activity of SubPc/Ti3C2Tx towards hydrogen production†

The production of hydrogen fuel by solar-driven photocatalytic water splitting is an attractive solution to overcome the environmental and energy problems with traditional fossil fuels. The strategies to improve the capacity of photocatalytic hydrogen production include enhancing the light absorption of materials and using co-catalysts to reduce the efficiency of electron–hole recombination. Here, we report a Schottky heterojunction photocatalyst composed of subphthalocyanine (SubPc) and Ti₃C₂T_x MXene, which can effectively separate photogenerated charges. The outstanding ability of SubPc to absorb visible light and the ability of Ti₃C₂T_x MXene to capture photogenerated electrons were applied to improve the photocatalytic hydrogen-production performance of the SubPc/Ti₃C₂T_x composite. Two types of SubPcs (SubPc-Cl and SubPc-OPh) were hybridized with Ti₃C₂T_x MXene nanosheets. The hydrogen evolution of SubPc/Ti₃C₂T_x with different mass ratios was experimentally investigated, and it was found that the optimized SubPc-Cl/Ti₃C₂T_x exhibited the best H₂-production rate of 105 μmol g⁻¹ h⁻¹. Our findings provide a new design approach and promising strategy to develop low-cost photocatalysts for future solar-driven sustainable energy-conversion systems.