In situ prepared ionic liquids containing moisture-resistant bismuth-based perovskite crystals enhance the photocatalytic water purification and H2 production of MOF

Perovskite materials have been found to enhance the photocatalytic performances of metal–organic frameworks (MOFs) through the formation of heterojunctions. In this study, two novel perovskite crystals: N-methylbenzothiazoleBiI 4 (BtzBiI 4 ) and 1,3-dimethylbenzimidazoleBiI 4 (MpiBiI 4 ) were obtained by in situ alkylation of 1-methylbenzimidazole and benzothiazole to prepare 1,3-dimethylbenzimidazole iodide and N-methylbenzothiazolium iodide ionic liquids. BtzBiI 4 and MpiBiI 4 crystals exhibit remarkable stability in aqueous solutions and broad UV–visible light absorption properties within 680 nm and 640 nm, respectively. Subsequently, a post-modification strategy was employed to integrate these perovskites with the zirconium-based MOF NH 2 -UiO-66 (U6N) and small-sized Pt clusters, resulting in the fabrication of perovskite quantum dots/Pt@U6N composite heterojunction photocatalysts for hydrogen production and water purification. Consequently, under visible light irradiation, the reduction efficiency of Cr (VI), degradation efficiencies rhodamine B (Rh B) and tetracycline (TC) of BtzBiI 4 QDs modified Pt@U6N (BPU) can reach 93.4 %, 98.9 % and 99.4 %, respectively. The H 2 production rate in water could be further boosted to 1044.25μmol g -1 h −1 by using BPU. Using MpiBiI 4 QDs modified Pt@U6N (MPU), the photocatalytic hydrogen production efficiency can reach 955.37μmol g -1 h −1 . This work comprehensively explores the role of ionic liquid-assisted preparation of moisture-resistant perovskites and their charge transfer dynamics in heterojunctions with MOFs, and introduces efficient photocatalysts for waste water purification.