<p>Photocatalysis provides a green way to produce hydrogen peroxide (H₂O₂) from oxygen and water. Although many materials with different structures have been designed for the photocatalytic production of H₂O₂, the supramolecular porous materials have been rarely reported. Herein, three imine-linked [3+6] type POCs, containing benzoxadiazole units with tunable functional groups (R = H, OMe, OH), named H-POC, OMe-POC, and OH-POC, are rationally fabricated for visible-light-driven generation of H₂O₂ in water and oxygen. The results show that performance is improved by regulating group from H, OMe, to OH, with the H₂O₂ yields of 527, 670, and 976 µmol h⁻¹ g⁻¹, respectively. Moreover, under the synergistic effect of light and heat (70 °C), the H₂O₂ production rate of OH-POC was further increased to 2748 µmol h⁻¹ g⁻¹. Photophysical and electrochemical studies have shown that functional group regulation enhances hydrophilicity, light absorption, and charge separation/transfer. In addition, the mechanism of the two-step 1e⁻ ORR and direct 2e⁻ WOR pathway for H₂O₂ production. Importantly, OH-POC shows extraordinary potential in the degradation of water environmental pollutants (tetracycline hydrochloride and mercaptobenzothiazole). This study provides a novel idea for the rational design of photocatalysts that rely on the POCs platform from the perspective of molecular structure design.</p>