Hydrogen peroxide photo-fuel cells

Abstract

Hydrogen peroxide (H₂O₂) possesses both strong oxidizing and moderate reducing ability. Due to the unique chemical reactivity, one-compartmentalization of fuel cells is possible by using H₂O₂ as both the fuel and oxidant for fuel cells (H₂O₂-FC). To enhance the anode reaction (H₂O₂ → O₂ + 2H⁺ + 2e⁻) of the H₂O₂-FC, a noble metal-free H₂O₂-photo fuel cell (PFC) has been newly developed for enhancing the conversion from chemical energy to electric energy with only emission of water and oxygen. The H₂O₂-photo fuel cells (PFC) take several significant advantages over the conventional hydrogen-oxygen fuel cells. With the realization of a solar-driven energy cycle with H₂O₂ as the key substance in mind, this Frontier article highlights the H₂O₂-PFCs. Firstly, the fundamentals of the H₂O₂-PFC are dealt with by treating the prototype using TiO₂ as the photoanode. Then, recent progress in the H₂O₂-PFCs and an emerging application to self-powered biosensors are described. Finally, the conclusions are summarized with the future outlook.