Water Dissociation Boosted-H₂O₂ Photoproduction via Molecular and Surface Engineering of Conjugated Porous Polymers.

Abstract

Solar-driven H₂O₂ photosynthesis in sacrificial-agent-free systems not only suffers from sluggish charge separation and migration efficiency, but also is fundamentally bottlenecked by the proton supply mismatch, the inability to extract protons efficiently from water dissociation. Herein, a dual-channel engineering strategy is proposed to overcome this bottleneck by synchronizing internal exciton dissociation with interfacial mass transfer in sulfonated spirobifluorene-based conjugated porous polymers. By coupling topological monomer linkage optimization with surface-grafted sulfonate groups, the water dissociation can be accelerated under strong alkalinity, leading to an exceptional H₂O₂ production rate of 8.19 mmol g^-1 h^-1 under pH = 11, and an excellent antimicrobial activity (>99% inactivation in 30 min). Critically, we provide direct spectroscopic and kinetic proof for a robust interfacial Vehicle mechanism that effectively bypasses bulk-phase thermodynamic limits under alkaline conditions. This interfacial boost is integrated with a significantly amplified molecular dipole and a minimized electron-hole overlap integral, ensuring near-spontaneous exciton decoupling and long-lived charge-separated states as corroborated by femtosecond transient absorption. This work establishes a new paradigm in catalyst design through synergistic molecular and water microenvironmental engineering for efficient solar-driven H₂O₂ production.