Photocatalytic Hydrogen Peroxide Production from Water Using a Cyano-Covalent Organic Framework

The demand for sustainable chemical production methods has led to significant advancements in photocatalysis. This study explores the photocatalytic production of hydrogen peroxide (H₂O₂) from water using a covalent organic framework (CYANO-COF) synthesized from triformylphloroglucinol (Tp) and 4,4'-diamino-[1,1'-biphenyl]-3,3'-dicarbonitrile (Bp-CN) via Schiff-base condensation. The synthesized COF material exhibited a predominantly AB stacking structure with an optimal band gap (2.22 eV) for visible-light absorption and effective charge separation. Furthermore, the photoelectrochemical characterizations revealed the photoresponsive nature of the material by creating a high charge density under illumination. Under illumination, the photocatalyst demonstrated efficient H₂O₂ generation with production rates of 550 μmolg^-1h^-1 using only water and 371 μmolg^-1h^-1 in the presence of ethanol. The sacrificial-agent-free system aligns with green chemistry principles, simplifying reaction conditions and reducing the environmental impact. Mechanistic studies confirmed the role of photoinduced electron-hole pairs in water oxidation and oxygen reduction. This research underscores the potential of CYANO-COF materials in sustainable H₂O₂ production using only water and sunlight thus highlighting avenues for optimizing long-term stability and efficiency.