Spatially Separated Redox Centers in Anthraquinone‐grafted Metal‐Organic Frameworks for Efficient Piezo‐photocatalytic H ₂ O ₂ Production

Piezo-photocatalytic production of hydrogen peroxide (H₂O₂) from water and air is promising but its large-scale application is still challenging as insufficient reaction active sites and low reaction efficiency. We have applied molecular engineering methods to design an anthraquinone molecularly (AQ) grafted metal-organic framework piezo-photocatalyst (UiO-66-AQ) for H₂O₂ generation from water and air. The catalyst achieves a peak H₂O₂ yield of 7872.4 μM g^-1 h^-1 by facilitating two critical reactions: single-electron water oxidation (WOR) and two-electron oxygen reduction (ORR) on spatially separated redox sites. Experiments and computational simulations reveal efficient charge separation through a ligand-to-chain transfer mechanism. Electrons and holes are selectively transferred to AQ and UiO-66 promoting ORR and WOR under ultrasound and visible light. The high reaction rate of ORR (rapid generation of endoperoxide) compensates for the slow kinetics of WOR (generation of OH*) and greatly increases the rate of full-reaction of H₂O₂ production. Additionally, a continuous flow tubular reactor equipped with UiO-66-AQ catalytic membranes affords 96 % removal of organic dyes by a in situFenton process under visible light and water flow, confirming the significant potential of the catalyst for practical applications. This work deepens the understanding of directional carrier migration at piezo-photocatalytic spatial separation sites, opening new pathways for environmentally friendly and efficient H₂O₂ synthesis.