Facile synthesis of CuO nanoparticles deposited zeolitic imidazolate frameworks (ZIF-8) for efficient photocatalytic dye degradation

Abstract

Herein, we investigated the synthesis and characterization of new CuO nanoparticles (CuO NPs) deposited Zeolitic Imidazolate Frameworks (ZIF-8) photocatalyst with higher catalytic ability for dye degradation. ZIF-8 cubes (∼ 80 nm) were synthesized via a sol-gel method. CuO NPs were deposited on the cubic ZIF-8 surfaces through in-situ nucleation and growth process. The structures and morphology of the CuO NPs/ZIF-8 nanocomposites were established with the results of PXRD analysis, transmission electron microscopic (TEM) images, optical properties, FT-IR spectroscopy and thermo gravimetric analysis (TGA). The as-synthesized material was selected as a photocatalyst to decompose rhodamine 6G (Rh6G) dye. The ultra-small colloidal CuO nanoparticles (~ 5 nm) deposited ZIF-8 photocatalyst exhibited efficient photocatalytic activity for Rh6G degradation under sunlight irradiation. The Rh6G degradation followed a pseudo-first-order kinetics model. Nanocomposite containing 5-wt% of CuO nanoparticles content exhibits highest photocatalytic activity towards dye degradation. The CuO NPs deposited ZIF-8 also worked effectively over a wide pH range from 5.0 to 12.0 and showed high degradation efficiency in alkaline environment. Rh6G dye degradation is enhanced significantly in H2O2 solution. The possible pathway for photocatalytic degradation of Rh6G dye in nanocomposites was proposed. The results indicated that nanocomposites can be used as a highly efficient photocatalyst to decompose organic pollutants.