Precious Metal‐Free Artificial Leaf for Photosynthesis of Hydrogen Peroxide from Water

Hydrogen peroxide (H 2 O 2 ) is recognized as an environmentally friendly oxidant with a wide range of applications, as well as a promising future energy carrier compared to hydrogen. Light driven and electrochemical production of H 2 O 2 have gained significant interest as promising alternatives to the energy‐intensive anthraquinone process. The two main approaches for the (photo)electrochemical production of H 2 O 2 are the water oxidation reaction (WOR) and the oxygen reduction reaction (ORR). Considering the scarcity of noble metals, it is critical to develop successful high‐performing electrocatalysts based on earth‐abundant sources, thus adhering to principles of Green and Sustainable Chemistry. Herein, the use of the recently developed FeO x nanoparticles (NP) catalyst as a photocathode, circumventing catalyst deactivation and oxidation, is reported. The FeO x NP photocathode exhibited an increased catalytic current by 41% under illumination, demonstrating the advantage of a photoelectrochemical (PEC) setup. Combining the FeO x NP photocathode for ORR with a Ti‐doped α‐Fe 2 O 3 photoanode for WOR, robust PEC performance is successfully achieved in bias‐free conditions. The structural integrity of the FeO x NP photocathode is preserved without degradation or oxidation for extended periods of irradiation of up to 10 h testimony of a benign and robust process.