Photocatalytic Degradation of Effluent water by CuO@Ag Core–shell Nanoparticles as Effective Catalyst under Irradiation of UV-light

Abstract

Photocatalytic degradation of Sulfur dye present in effluent water was studied using CuO@Ag core–shell nanoparticles as an active catalyst. In the present study, photocatalyst CuO@Ag core–shell nanoparticles were prepared by a simple cost effective wet chemical method at room temperature. The structural, optical and morphological properties of the synthesized powder were studied using different characterization techniques. The crystallinity, average crystallite size and the structure of CuO@Ag core–shell nanoparticles were analyzed using the X-ray diffraction (XRD) technique. The result showed crystalline nature and the monoclinic structure and FCC structure of CuO and Ag. The average crystallite size was estimated as 30 nm. X-ray photoelectron spectroscopy (XPS) technique was carried out to investigate the elemental composition and chemical state of CuO@Ag core–shell nanoparticles. This study confirmed the formation of the core–shell structure where Ag shell coated over CuO. UV–Visible absorption Spectroscopy was employed to determine the band gap energy of CuO@Ag core–shell nanoparticles. Fourier Transform Infrared Spectroscopic (FTIR) analysis indicated the presence of characteristic vibration modes of both CuO and Ag. High-Resolution Scanning Electron Microscopy (HR-SEM) was used to perform morphological analysis, which indicated the shape and particle size range of 30 – 70 nm. Energy Dispersive Spectroscopy (EDS) confirmed the chemical composition and purity of CuO@Ag core–shell nanoparticles. High-Resolution Transmission Electron Microscopy (HR-TEM) images of CuO@Ag core–shell nanoparticles revealed the core–shell structure of the prepared powder. Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and Differential Scanning Calorimeter (DSC) tests showed that CuO@Ag core–shell nanoparticles had good thermal stability, due to its high residual mass. Owing to its smaller crystallite size and higher surface area, photocatalytic degradation showed 97 % performance using CuO@Ag core–shell nanoparticles as photocatalyst. This result showed that CuO@Ag core–shell nanoparticles exhibited enhanced photocatalytic activity under UV light and thus the synthesized material is suitable for wastewater management.