Effective H2O2 Photosynthesis in Gas–Liquid–Solid Triphase System with Self‐Floating Conjugated Organic Polymers

Abstract Solar‐driven photocatalytic oxygen reduction is a promising pathway for sustainable hydrogen peroxide (H 2 O 2 ) production. However, limited O 2 diffusion and low selectivity in the two‐electron oxygen reduction reaction hinder its practical application. Here, a novel conjugated organic polymer material (conjugated triazine‐thiophene polymer, CTTP) based on triazine and thiophene, integrating a favorable mass transfer structure with competent catalytic centers is presented for the first time. Remarkably, under the gas–liquid–solid triphase condition, the self‐floating CTTP can rapidly capture gaseous oxygen, reducing it to superoxide radicals and transferring them to the reaction interface, drastically enhancing H 2 O 2 yield. An excellent H 2 O 2 concentration of 1.85 m m g −1 h −1 is achieved in a triphase system, representing a remarkable 14‐fold improvement compared to the liquid and solid phase reaction. Interestingly, the triphase system based on CTTP demonstrates the potential for large‐scale H 2 O 2 production under 8 h of sunlight irradiation, reaching 293 ppm day −1 m −2 . This work opens up a new avenue for the construction of sustainable H 2 O 2 production systems and may stimulate future related research.