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

TL;DR

This paper presents a sustainable method to produce hydrogen peroxide using a metal-free artificial leaf system that efficiently converts water under light.

Contribution

The study introduces FeOx nanoparticles as a stable and efficient photocathode for H2O2 production without precious metals.

Findings

FeOx NP photocathode increased catalytic current by 41% under illumination.

Combining FeOx NP with Ti-doped α-Fe2O3 photoanode achieved robust bias-free PEC performance.

The system maintained structural integrity for up to 10 hours of irradiation.

Abstract

Hydrogen peroxide (H2O2) 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 H2O2 have gained significant interest as promising alternatives to the energy‐intensive anthraquinone process. The two main approaches for the (photo)electrochemical production of H2O2 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 FeOx nanoparticles (NP) catalyst as a photocathode, circumventing catalyst deactivation and oxidation, is reported. The FeOx NP photocathode exhibited an increased catalytic current by 41% under illumination, demonstrating the advantage of a photoelectrochemical (PEC) setup. Combining the FeOx NP photocathode for ORR with a Ti‐doped α‐Fe2O3 photoanode for WOR, robust PEC performance is successfully achieved in bias‐free conditions. The structural integrity of the FeOx 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.

This work explores the photoelectrochemical production of H2O2 via oxygen reduction reaction and water oxidation reaction. It emphasizes the need for earth‐abundant photoelectrocatalysts and presents FeOx nanoparticles as stable, efficient photocathode material. Combined with a Ti‐doped α‐Fe2O3 photoanode, the system showed robust, bias‐free operation and long‐term stability.© 2025 WILEY‐VCH GmbH

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