Natural Anthraquinone‐Like Compound Extracted from Green Husk of Walnut Improves Photocatalytic <scp> H ₂ O ₂ </scp> Production Catalyzed by <scp> TiO ₂ </scp> Nanoparticles

Hydrogen peroxide (H 2 O 2 ) is a vital oxidant with broad industrial applications, and its production via photocatalysis represents a highly promising approach. Titanium dioxide (TiO 2 ) has garnered significant attention for photocatalytic H 2 O 2 generation. In this study, a simple method was used to enhance the photocatalytic performance by loading juglone as a co‐catalyst onto anatase TiO 2 . The quinone group of juglone serves as an efficient electron acceptor, effectively capturing conduction band electrons from TiO 2 to form stable semiquinone radical anions. Simultaneously, the phenolic hydroxyl group acts as a hole‐trapping site, promoting hole migration to the surface. This dual‐pathway charge separation mechanism substantially suppresses electron–hole recombination and improves quantum efficiency. Consequently, under illumination, the Juglone/TiO 2 photocatalyst achieved an H 2 O 2 production rate of 5851.44 μmol g −1 h −1 in an aqueous benzyl alcohol (as the hole scavenger) solution under an air atmosphere within 1 h. This work offers a new strategy for developing efficient and stable catalysts for solar fuel production.