Redox dual-cocatalysts modified ZnIn2S4 hollow sphere with spatially separated carrier for photocatalytic H2 production coupled with selective benzyl alcohol oxidation

• • The MnO2@ZnIn2S4@Ti3C2 hollow sphere achieves H2 production rate of 6.29 mmol g−1 h−1 and benzaldehyde production rate of 5.26 mmol g−1 h−1, representing a 3.2-fold and 2.8-fold enhancement over pristine ZnIn2S4, respectively, demonstrating the efficacy of spatially separated dual-cocatalysts in boosting redox reaction kinetics. • • The sandwich architecture with MnO2 (inner) and Ti3C2 (outer) creates a built-in electric field that drives photo-generated electrons to Ti3C2 and holes to MnO2, as confirmed by in situ XPS, leading to a 4.5-fold increase in photocurrent density compared to ZnIn2S4, indicating superior charge separation efficiency. • • The hollow sphere morphology increases specific surface area to 87.6 m2/g and enhances light absorption by 35% in the visible region (400-700 nm) due to multiple light scattering, as measured by UV-Vis DRS, which is critical for maximizing photon utilization in practical solar-driven applications. • • In situ EPR and DRIFTS analyses identified benzyl alcohol oxidation intermediates (e.g., ·CH2OH radicals and benzaldehyde) and confirmed that the reaction proceeds via a hole-mediated pathway, with a selectivity of 99.2% for benzaldehyde, highlighting the potential for selective oxidation of biomass-derived alcohols to high-value carbonyls.