Defect Anchoring [S-Ni-P] Interfacial Channel Regulating Charge Migration for Efficient Photoelectrochemical Water Splitting

Regulating bulk charge carrier transfer and surface catalytic reaction kinetics is thought a big challenge to photoelectrochemical (PEC) water splitting. Herein, the dual sites of CoNiP are delicately introduced into ZnIn2S4 (RZIS-CoNiP) nanosheet arrays via a defect anchoring method. The paving [SNiP] interfacial bond like a "bridge" can greatly reduce the phase resistance, improve the charge separation and migration, and promote the surface oxygen evolution reaction (OER) reaction. As expected, the optimized RZIS-CoNiP photoanode achieved a maximum photocurrent density of 4.77 mA cm-2 at 1.23 V versus reversible hydrogen electrode (RHE) in neutral electrolyte solution without the presence of any sacrificial agents, which is approximate to 12 times higher than that of the pristine ZnIn2S4 under AM 1.5G illumination. And the amount of oxygen evolution for the RZIS-CoNiP photoanode is as high as 21.9 mu mol in 3 h. Transient spectroscopy measurements and density functional theory (DFT) calculations in situ discovered the mechanism of defect anchoring [SNiP] bond on regulating charge transfer and surface reaction processes. This work provides a feasible anchoring interface route through defect engineering to regulate charge carrier transfer for PEC water splitting. Like the "Magpie bridge" in the Milky Way for the Cowherd and the Girl Weaver in an ancient Chinese love story, a novel strategy of defect anchoring [S-Ni-P] interfacial channels are paved between RZIS and CoNiP phase as the barrier-free "Bridge" for regulating the charge migration and separation toward efficient PEC water splitting. image