Amberlite-Integrated Resorcinol–Formaldehyde Resins for Photocatalytic Generation of Hydrogen Peroxide

Photocatalytic production of H₂O₂ from water and from O₂ by sunlight is an attractive strategy for liquid solar fuel production. The resorcinol-formaldehyde (RF) semiconducting resins are promising photocatalysts for H₂O₂ generation. However, the RF resins consist of large spherical particles with small surface areas (∼1 m² g^-1) owing to slow polymerization. In the present work, we synthesized RF resins in the presence of powdered Amberlite (AL) cation-exchange resins under the high-temperature hydrothermal conditions. This procedure produced small AL-integrated RF (RF@AL) resin particles with enlarged surface areas (∼62 m² g^-1) because the large numbers of electrophilic styrene-divinylbenzene moieties produced many polymerization nuclei. The RF@AL resins efficiently catalyzed water oxidation and O₂ reduction and generated 1.3 times as much H₂O₂ as the pristine RF, with the apparent quantum yield (Φ_AQY) at 420 nm being more than 10%.