Integrating S‐Scheme Heterojunction with Interfacial Metal‐Sulfur Bonds Promotes Solar‐to‐Hydrogen Evolution in TiO 2 @Pd‐Doped ZnIn 2 S 4 Core@Shell Photocatalysts

ABSTRACT Developing an efficient photocatalysis system enriched with charge transfer multi‐channels at the atomic level is significant in promoting the efficiency and stability of catalysts for H 2 production. In this work, through partial Zn 2+ replacement with Pd 2+ in ZnIn 2 S 4 (ZIS) nanosheets grown on TiO 2 microspheres, a Pd‐doped ZIS wrapped TiO 2 (TiO 2 @Pd‐ZIS) core@shell composite featuring multi‐function is fabricated. The TiO 2 @Pd‐ZIS photocatalyst exhibits excellent photocatalytic hydrogen evolution (PHE) performance in deionized water using triethanolamine (TEA) as a sacrificial agent, and it also has potential in tap water, lake water, simulated seawater, and antibiotic‐containing systems. As a proof of concept, a S‐scheme heterojunction is constructed in the TiO 2 @Pd‐ZIS, where the Ti─S bonds act as interfacial charge transfer channels, and the presence of Pd 2+ significantly broadens the light response range and enhances the intensity of the internal built‐in electric field (IEF) at the heterojunction interface. Driven by the Pd─S bonding interaction, the directional migration of charges is achieved, thereby generating new H * adsorption sites that are closer to the thermodynamically neutral state, which is conducive to efficient PHE. It demonstrates that the S‐scheme heterojunction and interfacial metal‐sulfur bond integrating could achieve enhanced charge transfer with synergy of optimized H * adsorption behavior for high‐performance hydrogen production.