Boosting the photocatalytic performance via defect-dependent interfacial interactions from electrostatic adsorption to chemical bridging

The sluggish kinetics of interfacial electron transport and suboptimal photocatalytic stability are remaining challenges for designing efficient hetero-structured photocatalysts. Herein, we demonstrate a defect-induced interfacial interaction in the graphene oxide quantum dot/indium sulfide (GQD/In₂S₃) hybrid, achieving remarkable stability and efficiency. By introducing sulfur vacancies into the In₂S₃ structure, the interfacial electron exchange between the GQD and In₂S₃ drastically increases, turning the interfacial interaction from weakly electrostatic adsorption to strongly chemical bridging. The interfacial interaction transition exhibits a great advantage in kinetics of interfacial electron transport with 12.32 times increase in the internal electric field intensity and less than half of carrier transport activation energy, while preventing the sulfur leaching in In₂S₃ and enhancing the photocatalytic stability. Consequently, the GQD/In₂S₃ with chemical bridging interface exhibits a dominant photocatalytic activity, with 40.9 mmol g⁻¹ h⁻¹, 22.7 folds higher than the analogous materials without S vacancies, and 96.1% H₂ yield retention after 100 h tests. The deep understanding of the defect-induced interfacial modulation provides an insight for the design of high-performance hybrid photocatalyst.