Molecular regulation on covalent triazine frameworks for boosting H2O2 photosynthesis in air atmosphere

Three CTFs are prepared to alter the microenvironment by introducing varying amounts thiophene units with electron donating in the skeleton. The synergistic interaction between electron-donating thiophene units and electron-withdrawing triazine units leads to a threefold increase in H2O2 photosynthesis. Importantly, CTF-Q3 achieves comparable H2O2 production efficiency in an air atmosphere as in an oxygen rich atmosphere, thereby enhancing its practical applicability. [Display omitted] •The precise regulation of CTFs skeleton through molecular design is achieved.•Efficient H2O2 photosynthesis is achieved in air condition, promoting application.•The combination of D-A units and triazine active sites promote charge separation. Hydrogen peroxide (H2O2) photosynthesis has garnered significant interest due to its advantages over traditional methods. However, currently, research on H2O2 photosynthesis typically requires high-concentration oxygen environments, liniting practical applications. Thus, achieving efficient H2O2 generation in ambient air is crucial for advancing this technology. Herein, three covalent triazine frameworks (CTFs) are prepared to alter the microenvironment by introducing varying amounts thiophene units with electron donating in the skeleton. The performance of H2O2 photosynthesis progressively improves with the addition of thiophene units in the skeleton, leading to a 3-fold increase in efficiency for CTF-Q3 compared to the initial CTF-Q1. Notably, CTF-Q3 achieves comparable H2O2 production efficiency and apparent quantum yield (AQY) in an air atmosphere (11.3 μmol/h, AQY = 6.9 % at 420 nm) as in an oxygen rich atmosphere (12.3 μmol/h, AQY = 7.8 % at 420 nm), due to the synergistic effect of the electron-donating thiophene units and electron-withdrawing triazine units. This finding is crucial for advancing the practical application of H2O2 photosynthesis.