Synthesis of CsPbBr₃ Decorated ZIF-8 Nanocomposite for Enhanced Photocatalytic Performance

CsPbBr₃ (CPB) perovskite nanocrystals (NCs) have attracted considerable interest due to their outstanding charge carrier mobility, long diffusion lengths, and efficient visible light absorption, making them ideal candidates for photocatalysis, light-emitting diodes (LEDs), solar cells, and photodetectors. However, their practical applications are limited by poor environmental stability. We employed a metal-organic framework (MOF) to address this challenge as a stabilizing matrix, selecting ZIF-8 for its exceptional thermal and chemical stability, high surface area, and versatile synthesis routes. The CPB/ZIF-8 nanocomposite was synthesized by integrating hot-injection-produced CPB nanocrystals with ZIF-8 using an optimized mixing approach, ensuring a uniform NCs distribution. Electron microscopy (EM) analysis confirmed the well-controlled and uniform distribution of the NCs on the surface of the ZIF-8. Moreover, the Fourier-transform infrared spectroscopy (FTIR) revealed ligand exchange, where the imidazole linkers of the ZIF-8 structure replace the NCs ligands. The process promotes almost epitaxial attachment of the latter, thus promoting effective charge interactions in the integration process. The unshifted absorbance spectra verified the preservation of optical activity, whereas a 92% quenching in photoluminescence (PL) indicated efficient charge separation and reduced electron-hole recombination. To investigate charge transfer mechanisms, photocatalytic dye degradation under visible light irradiation was employed using methyl orange (MO) and bromocresol green (BCG) as model dyes. The CPB/ZIF-8 nanocomposite exhibited significantly enhanced photocatalytic performance, achieving 1.48 and 1.75 times higher degradation rates for MO and BCG, respectively, compared to pristine CPB NCs. Electron paramagnetic resonance (EPR) studies demonstrated superior radical generation capabilities, particularly hydroxyl radicals (•OH), further confirming enhanced charge transfer and photocatalytic efficiency. These findings underscore the synergistic interaction between CPB NCs and ZIF-8, positioning the CPB/ZIF-8 nanocomposite as a promising material for photocatalysis and optoelectronic applications.