Immobilization of copper(i) oxide nanoparticles on porous carbon derived from a zeolitic imidazolate framework and investigation of their photocatalytic properties

Abstract

In this study, zeolitic imidazolate framework-8 (ZIF-8) was first synthesized by a solvothermal method and then carbonized in an argon atmosphere furnace (ZIFC). Next, it was used to make composites with different contents of copper(I) oxide (n%ZIFC–m%Cu₂O, 10 ≤ m,n ≤ 90), which were applied as photocatalysts in the degradation of methylene blue (MB) dye under visible light. The surface morphology and elemental structure of the obtained compounds were investigated by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques were also employed to evaluate the chemical and crystalline structure of the synthesized composites, respectively. In addition, the specific surface area of the samples was analyzed using the Brunauer–Emmett–Teller (BET) measurements. The results showed that the ZIFC and ZIFC-based composite with different contents of Cu₂O (25%ZIFC–75% Cu₂O) were mesoporous and the increase of ZIFC content in the composite increased the specific surface area. Furthermore, the investigation of the photocatalytic activity of nanocomposites showed that the composite containing 25% ZIFC and 75% Cu₂O degraded 98% of MB dye within 60 minutes under visible light. This outstanding performance is attributed to the synergistic effect of Cu₂O and ZIFC, which enhances electron–hole separation and adsorption capacity, making this composite a promising candidate for the environmental applications.