Nafion-Integrated Resorcinol-Formaldehyde Resin Photocatalysts for Solar Hydrogen Peroxide Production

Photocatalytic generation of H₂O₂ from water and O₂ is a promising strategy for liquid solar-fuel production. Previously reported powder photocatalysts promote a subsequent oxidative/reductive decomposition of the H₂O₂ generated, thereby producing low-H₂O₂-content solutions. This study reports that Nafion (Nf)-integrated resorcinol-formaldehyde (RF) semiconducting resin powders (RF@Nf), synthesized by polycondensation of resorcinol and formaldehyde with an Nf dispersion solution under high-temperature hydrothermal conditions, exhibit high photocatalytic activities and produce high-H₂O₂-content solutions. Nf acts as a surface stabilizer and suppresses the growth of RF resins. This generates small Nf-woven resin particles with large surface areas and efficiently catalyze water oxidation and O₂ reduction. The Nf-woven resin surface, due to its hydrophobic nature, hinders the access of H₂O₂ and suppresses its subsequent decomposition. The simulated-sunlight irradiation of the resins in water under atmospheric pressure of O₂ stably generates H₂O₂, producing high-H₂O₂-content solutions with more than 0.06 wt % H₂O₂ (16 mM).