Sunlight-Driven Hydrogen Peroxide Production from Water and Molecular Oxygen by Metal-Free Photocatalysts

• Published in: Angewandte Chemie International Edition Vol. 53; no. 49; pp. 13454 - 13459
• Main Authors: Shiraishi, Yasuhiro, Kanazawa, Shunsuke, Kofuji, Yusuke, Sakamoto, Hirokatsu, Ichikawa, Satoshi, Tanaka, Shunsuke, Hirai, Takayuki
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Carbon nitride; Catalysis; Catalysts; Diimide; graphitic carbon nitride; Hydrogen peroxide; Irradiation; Oxidation; Oxygen; Palladium; photocatalysis; Reduction; Sunlight; Synthesis; water; photocatalysis; oxygen; water; graphitic carbon nitride; hydrogen peroxide
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201407938

Design of green, safe, and sustainable process for the synthesis of hydrogen peroxide (H2O2) is a very important subject. Early reported processes, however, require hydrogen (H2) and palladium‐based catalysts. Herein we propose a photocatalytic process for H2O2 synthesis driven by metal‐free catalysts with earth‐abundant water and molecular oxygen (O2) as resources under sunlight irradiation (λ>400 nm). We use graphitic carbon nitride (g‐C3N4) containing electron‐deficient aromatic diimide units as catalysts. Incorporating the diimide units positively shifts the valence‐band potential of the catalysts, while maintaining sufficient conduction‐band potential for O2 reduction. Visible light irradiation of the catalysts in pure water with O2 successfully produces H2O2 by oxidation of water by the photoformed valence‐band holes and selective two‐electron reduction of O2 by the conduction band electrons. Peroxide made by sunbathing: Sunlight irradiation (λ>400 nm) of graphitic carbon nitride (g‐C3N4) containing electron‐deficient aromatic diimide units successfully produces H2O2 from water and O2. This metal‐free H2O2 synthesis is driven by oxidation of water by the photoformed valence‐band holes and selective two‐electron reduction of O2 by the conduction‐band electrons.