Enhanced carbon dioxide reduction in a thin-film rotating disk photocatalytic fuel cell reactor

Abstract A thin-film rotating disk photocatalytic fuel cell (PFC) reactor provided an enhanced photocatalytic reduction of CO2 to CH4. The yield of CH4 in this system was measured to be 7.62 μmol g−1 h−1, which was 2.7 times higher than that in the commonly used bubbling method. This photocatalytic reactor allowed CO2 to diffuse through the thin film emerged on the rotating cathode, and a high solubility of CO2 in the aqueous electrolyte solutions was obtained. This enabled the effective utilization of CO2 on the interface between the aqueous solution and the rotating cathode without the traditional bubbling method, thereby boosting the photocatalytic reduction rate of CO2 to CH4. Additionally, the influences of the rotation speed, electrode immersion level and pH value on the PFC performance were investigated. The thin-film photocatalytic system offers an efficient and low-cost method to facilitate CO2 reduction.