Anthraquinone-Induced asymmetric antimony coordination center for selective O₂ photoreduction to H₂O₂

Achieving O₂ photoreduction to H₂O₂ with high selectivity control and durability while using easily accessible catalyst requires new synthesis strategies. Herein, we propose an asymmteric Sb coordination active center strategy of introducing anthraquinone (AQ) and heptazine to form local N₃ - Sb - O coordination by a rapid and simple explosive crystallization approach, resulting in a mesoporous conjugated heptazine-amide-AQ polymer coordinated Sb (HAAQ-Sb). It is demonstrated that the N₃ - Sb - O coordination effectively suppresses the charge recombination and acts as the highly active site for O₂ adsorption. Moreover, as-introduced AQ units initiate low-barrier hydrogen transfer through a reversible redox process that triggers highly-efficient H₂O₂ production. A superior apparent quantum yield of 20.2 % at 400 nm and a remarkable solar-to-chemical conversion efficiency of 0.71 % are achieved on the optimal HAAQ-Sb, which is the highest among C₃N₄-based photocatalysts at present. This asymmetric coordination concept and material design method provide new perspectives for the research of novel catalysts toward artificial photosynthesis.