Spatially Separated Redox Centers in Anthraquinone‐grafted Metal‐Organic Frameworks for Efficient Piezo‐photocatalytic H <sub>2</sub> O <sub>2</sub> Production
Cheng Chen, Kangsheng Gu, Peifang Wang, Zhao‐Qing Liu, Yanhui Ao
Abstract
Abstract Piezo‐photocatalytic production of hydrogen peroxide (H 2 O 2 ) 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 H 2 O 2 generation from water and air. The catalyst achieves a peak H 2 O 2 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 H 2 O 2 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 H 2 O 2 synthesis.