A facile synthesis of hollow SiO2@g-C3N4@AgBr for efficient photocatalytic production of H2O2

A novel hollow SiO₂@g-C₃N₄@AgBr photocatalyst was fabricated for efficient H₂O₂ production. • The Z -scheme heterojunction endow the catalyst with a narrow band gap of 1.25 eV and superior charge separation efficiency. • The catalyst exhibits a dual-channel pathway to achieve a high H₂O₂ yield up to 1392.84 μmol h −1  g −1 . Using PVP-modified polystyrene (PS) microspheres as a template, and tetraethyl orthosilicate (TEOS), melamine, AgNO₃, and KBr as precursors, a novel mesoporous hollow SiO₂@g-C₃N₄@AgBr ternary composite photocatalyst with a porous surface was readily prepared via a one-pot method. The composite structure was obtained by simple calcination without further chemical reduction. The structure and morphology of the catalyst were characterized by XRD, UV–Vis DRS, SEM, TEM, and XPS. The results revealed that the hollow SiO₂ microspheres provided a high specific surface area, and the band gap of the composite was narrowed to 1.25 eV, endowing the hollow composite with excellent broad-spectrum photocatalytic performance. The catalyst achieved efficient photocatalytic H₂O₂ production from water under ambient air, and the maximum productivity reached 1392.84 μmol·g −1 ·h −1 within 1 h with the aid of different sacrificial agents. Finally, the catalytic mechanism was investigated. The as-prepared catalyst exhibited a unique dual-channel pathway based on a Z -scheme heterojunction, which significantly boosted H₂O₂ production and environmental adaptability. Download: Download high-res image (65KB) Download: Download full-size image