Dipole field as charge-transfer bridge between Cu atomic clusters/PtCu alloy nanocubes and nitrogen-rich C₃N₅ for superior photocatalytic hydrogen evolution

Utilizing spontaneous polarization field to harness charge transfer kinetics is a promising strategy to boost photocatalytic performance. Herein, a novel Cu atom clusters/PtCu alloy nanocubes coloaded on nitrogen-rich triazole-based C₃N₅ (PtCu-C₃N₅) with dipole field was constructed through facile photo-deposition and impregnation method. The dipole field-drive spontaneous polarization in C₃N₅ acts as a charge-transfer bridge to promote directional electron migration from C₃N₅ to Cu atom clusters/PtCu alloy. Through the synergistic effects between Cu atom clusters, PtCu alloy and dipole field in C₃N₅, the optimized Pt₂Cu₃-C₃N₅ achieved a record-high performance with H₂ formation rate of 4090.4 μmol g^-1 h^-1 under visible light, about 154.4-fold increase compared with pristine C₃N₅ (26.5 μmol g^-1 h^-1). Moreover, the apparent quantum efficiency was up to 25.33 % at 320 nm, which is greatly superior than most previous related-works. The directional charge transfer mechanism was analyzed in detail through various characterizations and DFT calculations. This work offers a novel pathway to construct high-efficiency multi-metal photocatalysts for solar energy conversion.