Heteroatom-fused tetraphenylethylene-based conjugated microporous polymers for sacrificial photocatalytic H2O2 production

Hydrogen peroxide (H 2 O 2 ) is an extremely valuable feedstock and environmentally friendly oxidising agent widely used in the modern chemical industry. While current industrial methods for H 2 O 2 synthesis are energy-intensive, photocatalysis presents a sustainable alternative. However, the efficiency of existing photocatalytic systems remains insufficient for practical large-scale applications. Herein, a range of tetraphenylethylene-based conjugated microporous polymers (CMPs) have been designed and synthesized through Suzuki-Miyaura polycondensation, incorporating either biphenyl, dibenzo[ b,d ]thiophene, or dibenzo[ b,d ]thiophene sulfone. We investigate how the presence of dibenzo[ b,d ]-thiophene sulfone units correlates with enhanced photocatalytic activity, which is attributed to increased wettability and improved charge separation. The CMP which contains biphenyl ring functionality shows a H 2 O 2 production rate of 10,500 µmol h −1 g −1 , which more than doubles to 26,650 µmol h −1 g −1 upon incorporation of dibenzo[ b,d ]thiophene sulfone building blocks, with an apparent quantum yield of 17.1% at 420 nm. This work also explores the stability of CMP photocatalysts for H 2 O 2 production and evaluates a potential superoxide radical-mediated mechanism.