Abstract: Tailoring the electronic interaction at the interface between semiconductor catalyst supports and deposited cocatalysts affords a refined strategy to precisely manipulate the electronic states of the active centers residing in the cocatalysts, and concomitantly promote their catalytic efficacy. Herein, we report the fabrication of Pt‑CCNS, a model system consisting of Pt nanoparticles supported on cyano-rich crystalline g-C₃N₄ nanosheet, which manifests highly uniform Pt dispersion and a strengthened interfacial electronic interaction with the underlying g-C₃N₄. Compared with conventional Pt nanoparticle-modified g-C₃N₄ (Pt-CN), the introduced cyano groups in Pt‑CCNS play a dual role. They not only enable uniform dispersion of Pt cocatalysts on the crystalline g‑C₃N₄ surface, but also effectively promote charge transfer from the g-C₃N₄ substrate to Pt sites. This enhanced electron flow consequently optimizes the adsorption behavior of hydrogen reaction intermediates on the Pt active centers. Benefiting from the optimized electronic structure and interfacial charge transfer, the optimized Pt-CCNS_0.1 photocatalyst delivers a prominent hydrogen-evolution rate of 596.7 μmol h⁻¹, outperforming Pt‑CN by a factor of 2.8 and pristine g-C₃N₄ by a factor of 29.6. This investigation elucidates the intricate interfacial electronic interactions in cocatalyst-modified photocatalytic systems and, more importantly, establishes a robust paradigm for the rational construction of high-efficiency photocatalysts.

Key words: Photocatalysis, Hydrogen evolution, Crystalline g-C₃N₄, Cyano group, Electronic structure regulation