Abstract: Hydrogen-bonded organic frameworks (HOFs) hold substantial potential for application in photocatalysis. However, their practical application in photocatalytic H₂O₂ generation and antibacterial activity remains hampered by intrinsically inefficient electron-hole separation and inadequate structural stability. Herein, a Py-HOF photocatalyst was prepared by employing 1,3,6,8-tetrakis (p-benzoic acid) pyrene (H₄TBAPy) as precursor via self-assembly method, and the titanium dioxide/Hydrogen-bonded organic framework (TiO₂/Py-HOF, T/Py-HOF) S-scheme heterojunction was rationally fabricated via an in situ synthesis. Due to the strong hydrogen bonds and π-π interactions of H₄TBAPy, the T/Py-HOF S-scheme heterojunction displays super stability. Furthermore, in situ irradiated X-ray photoelectron spectroscopy (ISXPS), femtosecond transient absorption spectroscopy (fs-TAS), and density functional theory (DFT) calculations verify the S-scheme carrier migration mechanism within the T/Py-HOF heterojunction. Thanks to the ultrafast charge-transfer and excellent redox ability of the T/Py-HOF S-scheme photocatalyst, the optimally formulated T/Py-HOF-5% achieves a remarkable H₂O₂production rate of 1890 mmol g^-1 h^-1, corresponding to approximately 15.24 and 6.19-fold enhancements compare to the pure TiO₂ and bare Py-HOF, respectively, along with excellent stability. Furthermore, the T/Py-HOF heterojunction also exhibits superior photocatalytic sterilization activity against Escherichia coli (E. coli), achieving almost 100% of E. coli inactivation after 90 min light irradiation. Collectively, this work offers a novel insight for designing high-efficiency HOF-based S-scheme photocatalysts in energy and environment applications.

Key words: S-scheme, Hydrogen-bonded organic framework (HOF), Hydrogen peroxide, Photocatalytic sterilization, Femtosecond transient absorption spectroscopy