Crafting double perovskites/hollow conjugated microporous polymer heterostructure for dual-channel H2O2 production

Abstract

Visible-light-driven photocatalysis employing all-inorganic halide perovskites offers a sustainable and green approach for producing value-added H₂O₂. However, the practical efficiency of these catalysts is often hampered by undesirable charge recombination and insufficient light absorption. To overcome these limitations, Cs₂AgBiBr₆ (CABB) double perovskites were encapsulated into a porphyrin-based hollow conjugated microporous polymer (hPrFb CMPs) scaffold. The resulting CABB@hPrFb composite features matched orbital energy level structures, readily accessible catalytic sites and a robust hPrFb framework, collectively contributing to its superior photocatalytic performance. Remarkably, this heterojunction achieves an H₂O₂ production rate of 3500 µmol g⁻¹ h⁻¹ without the use of scavengers, along with an apparent quantum efficiency (AQE) of 9.66% at 420 nm. In contrast to its individual components, which primarily facilitate the oxygen reduction reaction (ORR), the heterostructure enables dual-channel H₂O₂ generation via both ORR and the water oxidation reaction (WOR). This work demonstrates that rational encapsulation of perovskites into tailorable hollow CMPs, coupled with built-in electric field (BIEF) engineering, provides a viable strategy for developing high-performance composite photocatalysts and opening new avenues for semiconductor-based photocatalytic applications.