Unassisted selective solar hydrogen peroxide production by an oxidised buckypaper-integrated perovskite photocathode

Hydrogen peroxide (H 2 O 2 ) is an eco-friendly oxidant and a promising energy source possessing comparable energy density to that of compressed H 2 . The current H 2 O 2 production strategies mostly depend on the anthraquinone oxidation process, which requires significant energy and numerous organic chemicals. Photocatalyst-based solar H 2 O 2 production comprises single-step O 2 reduction to H 2 O 2 , which is a simple and eco-friendly method. However, the solar-to-H 2 O 2 conversion efficiency is limited by the low performance of the inorganic semiconductor-based photoelectrodes and low selectivity and stability of the H 2 O 2 production electrocatalyst. Herein, we demonstrate unassisted solar H 2 O 2 production using an oxidised buckypaper as the H 2 O 2 electrocatalyst combined with a high-performance inorganic-organic hybrid (perovskite) photocathode, without the need for additional bias or sacrificial agents. This integrated photoelectrode system shows 100% selectivity toward H 2 O 2 and a solar-to-chemical conversion efficiency of ~1.463%.