Rationally designed dibenzothiophene-S,S-dioxide-based conjugated porous polymers for efficient photocatalytic hydrogen peroxide production

Conjugated porous polymers (CPPs) represent a novel class of photocatalysts for hydrogen peroxide (H 2 O 2 ) production. Their photocatalytic activity can be enhanced through rational design of the electronic structures. Herein, three donor–acceptor (D–A) type CPPs with expanded saddle-shaped structures were constructed by copolymerizing dibenzothiophene-S,S-dioxide with different electron donating units, including triphenylamine, 1,3,5-triphenylbenzene, and 2,4,6-triphenyltriazine. Among the prepared CPPs, the dibenzothiophene-S,S-dioxide-triazine-based polymer shows impressive photocatalytic H 2 O 2 production rate of 2.98 mmol g −1 h −1 under the optimal condition, which is among the top photocatalytic performance reported so far for the existing CPPs. Experimental and theoretical studies revealed that the introduction of triazine linkages not only prolongs carrier lifetime and increases charge separation efficiency, but also reduces the energy barrier for O 2 activation. This study elucidates that rational design of dibenzothiophene-S,S-dioxide-based photocatalysts by tailoring electron-donating strength, charge transfer orientation and O 2 adsorption sites is crucial for efficient H 2 O 2 production.