Interfacial GO charge-bridge engineering reconstructs S-scheme charge flux for photocatalytic H2 evolution

GO kinetically reconstructs intrinsic S-scheme charge flux without altering its thermodynamic direction. • The GO bridge accelerates directional interfacial charge migration. • Continuous charge redistribution regulates Cd-site H* adsorption energetics. Interfacial charge regulation is crucial for improving S-scheme photocatalysts, yet the kinetic role of carbonaceous interfacial bridges remains insufficiently understood. Herein, graphene oxide (GO) is introduced into a directly contacted g-C 3 N 4 /CdS S-scheme heterojunction to reconstruct its interfacial charge-transport network. The direct g-C 3 N 4 /CdS heterointerface determines the S-scheme charge-transfer direction through Fermi-level equilibration, band bending, and the resulting built-in electric field, whereas interfacially distributed GO primarily functions as an auxiliary charge bridge that strengthens electronic coupling and lowers the kinetic resistance of selective low-energy carrier recombination. In situ irradiated X-ray photoelectron spectroscopy and electron paramagnetic resonance, combined with work-function analysis, reveal directional photoinduced charge redistribution consistent with a GO-assisted S-scheme pathway. Photoluminescence, transient photocurrent, and electrochemical impedance spectroscopy further demonstrate suppressed charge recombination and improved interfacial carrier transport. Density functional theory calculations show that GO extends interfacial charge redistribution and shifts the calculated H* adsorption free energy at the Cd site closer to thermoneutrality relative to binary g-C 3 N 4 /CdS, yielding a ΔG H⁎ value of −0.29 eV. Consequently, g-C 3 N 4 /3GO/40CdS achieves a visible-light-driven H 2 evolution rate of 816.2 μmol g −1  h −1 , approximately 2.4 times that of binary g-C 3 N 4 /40CdS. Download: Download high-res image (179KB) Download: Download full-size image