One-Compartment Hydrogen Peroxide-Photofuel Cell Using TiO2 Photoanode and Prussian Blue Cathode

Abstract

We have studied the factors affecting the performances of one-compartment hydrogen peroxide photofuel cell (H2O2-PFC) consisting of TiO2 photoanode, cathode, and an aqueous electrolyte solution. As the photoanode, a dense TiO2 film was formed on fluorine-doped tin oxide by a dip-coating method (d-TiO2/FTO) with the thickness controlled below ∼0.5 μm, and a mesoporous TiO2 nanocrystalline film with a thickness of 3.6 μm was coated on FTO (mp-TiO2/FTO) by a doctor blade method. The d-TiO2/FTO provides performances superior to mp-TiO2/FTO in spite that the decrease in the surface area. Building a compact TiO2 underlayer by a spray method (d-TiO2/s-TiO2/FTO) results in further improvement of the cell performances. On the other hand, the replacement of glassy carbon cathode by Prussian Blue-electrodeposited FTO drastically increases the cell performances due to its excellent electrocatalytic activity for the H2O2 reduction. A one-compartment H2O2-PFC with the structure of d-TiO2/s-TiO2/FTO (photoanode) | 0.1 M NaClO4 and 0.1 M H2O2 (pH 3, electrolyte solution) | PB/FTO (cathode) exhibits short-circuit current (Jsc) of 1.57 mA cm−2 and open-circuit voltage (Voc) of 787 mV.