Nano-on-Micro BiOCl_0.6Br_0.4/Zn₃In₂S₆ Heterostructure with Prolonged Charge Separation and Exposed Bi Active Sites for...

The inefficient dynamics of photogenerated charge carriers and the limited accessibility of active sites remain concurrent challenges for achieving efficient solar-driven CO₂ photoreduction. Herein, a distinct nano-on-micro (NOM) BiOCl_0.6Br_0.4/Zn₃In₂S₆ heterostructure (NOM-BZ) is rationally constructed by precisely anchoring nano-BiOCl_0.6Br_0.4 onto micro-Zn₃In₂S₆ via an in situ seed-growth route. This architecture simultaneously optimizes charge kinetics and surface redox sites, thereby significantly enhancing the CO₂-to-CO conversion performance. In particular, NOM-BZ exhibits a prolonged average charge lifetime of 3102 ps (5-fold higher than pristine) and abundant electron-rich Bi active sites, especially Bi^(3-x)+ species, which efficiently drive CO₂ reduction. In addition, NOM-BZ facilitates CO₂ adsorption and activation and promotes *COOH intermediate formation by lowering the energy barriers, leading to noteworthy activity and long-term stability. This work highlights a robust NOM-engineered heterostructure capable of concurrently modulating charge dynamics and active-site chemistry, offering a promising paradigm for the rational design of next-generation photocatalysts for CO₂ conversion.