Metallic TiN Nanoparticle Cocatalyst with Hydrogen-Induced Nitrogen Vacancies for Plasmon-Enhanced Full Solar-Spectrum-Driven H₂ Production

Solar-driven hydrogen (H 2 ) production from water-splitting reactions has aroused intensive attention but is still challenging. Here, we report a hydrogen (H 2 )-induced nitrogen-defective metallic titanium nitride (TiN) cocatalyst-decorated zinc indium sulfide (ZnIn 2 S 4 ) nanoflower sphere for enhanced full solar-spectrum-driven H 2 production. The defective TiN cocatalysts with localized surface plasmon resonance (LSPR) effect obtained by thermal treatment in the H 2 atmosphere indicate reduced electrochemical resistance, rich surface active sites, and metallic features, and they were then decorated onto the ZnIn 2 S 4 nanoflower through a one-pot solvothermal process. The resultant hydrogenated TiN nanoparticle-decorated ZnIn 2 S 4 (TiN/ZnIn 2 S 4, TZ) composite reveals an extended light absorption range, resisted photocorrosion, and accelerated charge separation, demonstrating a highest H 2 yield rate of 2.4 mmol·g –1 ·h –1 irradiated by visible light (λ ≥ 420 nm). Meaningfully, the optimal TZ-150 composite could even produce H 2, excited by NIR light (1050 nm), realizing a full solar-spectrum-induced H 2 production. This work would offer an interesting avenue to employ plasmon transition metal nitrides in full solar-spectrum photocatalytic reactions.