Photoelectrochemical Hydrogen Peroxide Production from Water on a WO3/BiVO4 Photoanode and from O2 on an Au Cathode Without External Bias

• Published in: Chemistry, an Asian journal an Asian journal, 2017-05, Vol.12 (10), p.1111-1119
• Main Authors: Fuku, Kojiro, Miyase, Yuta, Miseki, Yugo, Funaki, Takashi, Gunji, Takahiro, Sayama, Kazuhiro
• Format: Article
• Language: English
• Subjects: Aqueous electrolytes; Au cathode; Bismuth oxides; Cathodes; Cathodic cleaning; Chemistry; Current efficiency; Degradation; Electrolytes; hydrogen carbonate; Hydrogen peroxide; Photoanodes; solar light; Vanadates; WO3/BiVO4 photoanode
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.201700292

The photoelectrochemical production and degradation properties of hydrogen peroxide (H2O2) were investigated on a WO3/BiVO4 photoanode in an aqueous electrolyte of hydrogen carbonate (HCO3−). High concentrations of HCO3− species rather than CO32− species inhibited the oxidative degradation of H2O2 on the WO3/BiVO4 photoanode, resulting in effective oxidative H2O2 generation and accumulation from water (H2O). Moreover, the Au cathode facilitated two‐electron reduction of oxygen (O2), resulting in reductive H2O2 production with high current efficiency. Combining the WO3/BiVO4 photoanode with a HCO3− electrolyte and an Au cathode also produced a clean and promising design for a photoelectrode system specializing in H2O2 production (ηanode(H2O2)≈50 %, ηcathode(H2O2)≈90 %) even without applied voltage between the photoanode and cathode under simulated solar light through a two‐photon process; this achieved effective H2O2 production when using an Au‐supported porous BiVO4 photocatalyst sheet. Making H2O2 with light: Combining the WO3/BiVO4 photoanode with an HCO3− electrolyte and an Au cathode achieved a clean and promising design for a photoelectrode system specializing in H2O2 production even without applied voltage between the photoanode and cathode under simulated solar light.