Hollow Conjugated Microporous Polymers Anchored With Zn x Cd 1‐x S Quantum Dots: An Additive‐Free Photocatalyst for H 2 O 2 Synthesis via S‐Scheme Charge Transfer

ABSTRACT Photocatalytic H 2 O 2 production via the two‐electron oxygen reduction reaction (2e − ORR) offers a green alternative to the anthraquinone process, but single‐component photocatalysts suffer from rapid charge recombination. Here, we construct an S‐scheme heterojunction by growing Zn x Cd 1‐x S (ZCS) quantum dots (QDs) in situ on hollow conjugated microporous polymers (CMPs) containing selenadiazole units ( h PSe). The hollow CMPs scaffold provides high surface area, abundant pores for QDs embedding, efficient mass transfer, and enhanced light harvesting, while the selenadiazole units promote strong interfacial coupling. In pure water without any sacrificial agent, the optimal ZCS@ h PSe‐2 composite achieved an outstanding H 2 O 2 production rate of 15.13 mmol g −1 h −1 with a synergy factor of 1.53 and an apparent quantum efficiency (AQE) of 8.82% at 400 nm, operating exclusively via the 2e − ORR. The dramatic performance is attributed to the S‐scheme charge transfer mechanism, which preserves the strong redox potentials of both components and suppresses bulk charge recombination. This work demonstrates that rational integration of QDs with hollow CMPs provides a viable pathway toward efficient, additive‐free photocatalytic H 2 O 2 synthesis.