TD-COF encapsulation of FeSe2/MoSe2 heterostructures for efficient peroxymonosulfate-activated photocatalysis

FeSe 2 /MoSe 2 @TD-COF heterostructure with integrated photocatalytic functions. • TD-COF shell enhances light absorption and interfacial reactant enrichment. • FeSe 2 /MoSe 2 heterojunction regulates charge separation and electron transfer. • Functional integration markedly improves peroxymonosulfate activation efficiency. • Rapid TCH degradation dominated by ·O 2 - and SO 4 · - radicals. A rationally designed core–shell heterostructure (FeSe 2 /MoSe 2 @TD-COF) is constructed via in situ growth of an imine-linked covalent organic framework on a FeSe 2 /MoSe 2 heterojunction for efficient peroxymonosulfate (PMS) activation under simulated sunlight irradiation. In this core–shell architecture, the FeSe 2 /MoSe 2 heterojunction serves as a charge-separation and electron-regulation center, while the TD-COF shell enhances light harvesting, reactant enrichment, and interfacial confinement, thereby synergistically promoting interfacial charge transfer and PMS activation. The optimized FM-5@TD-COF-9 achieves 96% tetracycline hydrochloride (TCH) removal within 60 min, with degradation rates 43 and 2.88 times higher than those of FeSe 2 /MoSe 2 and TD-COF, respectively. Radical-trapping experiments, electron paramagnetic resonance (EPR) measurements, and liquid chromatography-mass spectrometry (LC-MS) analysis reveal that superoxide radicals (·O 2 - ) and sulfate radicals (SO 4 · - ) are the dominant reactive species, while photogenerated holes (h + ) plays a secondary role and hydroxyl radicals (·OH) contributes only marginally, leading to three plausible TCH degradation pathways. This work highlights an effective heterostructure-based strategy for interfacial catalytic regulation in PMS-activated photocatalytic systems. Download: Download high-res image (148KB) Download: Download full-size image