Achieving a Simultaneous Charge- and Energy-Involved Dual-Channel Mechanism in Spirobifluorene-Based Conjugated Organic Polymers for Enhanced H 2 O 2 Photosynthesis

Current photocatalytic systems often focus on facilitating carrier separation and transfer to boost charge-involved H₂O₂ generation while overlooking the energy-involved process. The integration of both charge- and energy-involved processes within a single photocatalyst to achieve a dual-channel mechanism remains a significant challenge, despite its potential to maximize overall H₂O₂ production performance. Owing to the orthogonal configuration, spirobifluorene enables orthogonal carrier transport with multiple charge transfer pathways; through microenvironment engineering, intersystem crossing is enhanced for the prepared conjugated organic polymers (COPs), promoting efficient formation of the triplet excited state and extending its lifetime. The most efficient COP, TBSF-Py, which employs a pyridine unit as the cross-linker, shows both the lowest exciton binding energy and longest exciton lifetime, thereby promoting ¹O₂ generation and enabling dual-channel H₂O₂ photosynthesis via both charge- and energy-involved mechanisms. It achieves a H₂O₂ production rate of 7.21 mmol g^-1 h^-1 under air and pure water conditions and a solar-to-chemical conversion (SCC) efficiency of up to 1.88%. TBSF-Py also demonstrates robust performance under solar light irradiation (2.0 mM within 8 h), in triphasic floating (3.0 mM within 5 h), continuous-flow systems (12.4 mM within 9 h), and photocatalytic antimicrobial experiment (>99% inactivation within 30 min). These values are sufficient to meet the requirements for small-scale and household applications at the ∼mM level, thereby proving its comprehensive potential for practical applications. This work presents a simple and effective design strategy for the synthesis of organic photocatalysts featuring a dual-channel mechanism toward efficient H₂O₂ photosynthesis.