Cost-Effective Efficient Materials for Dye Degradation using Green and Facile Chemistry Routes

Abstract

Abstract In the present studies, the synthesis of Mg and S-doped ZnO nanoparticles was carried out using a non-aqueous sol-gel method. X-ray diffraction (XRD) techniques were used to examine the crystallisation of ZnO, Mg-ZnO, and S-ZnO samples. The Mg-ZnO and S-ZnO samples exhibit significant c-axis compression and smaller crystallite sizes as compared to undoped ZnO. To investigate the electronic, optical, and functional group characteristics of the nanoparticles, various spectroscopic techniques such as FTIR, X-ray photoelectron spectroscopy (XPS), UV/vis spectroscopy, and photoluminescence (PL) spectroscopy were employed. The optical band gap of Mg-ZnO and S-ZnO NPs were found to be 2.93 eV and 2.32 eV, respectively, which are lower than that of ZnO NPs (3.05 eV). The S-doped ZnO resulted in the homogenous distribution of sulfur ions in the ZnO lattice crystal. XPS analysis revealed that the doped S element was mostly S4+ and S6+. Furthermore, we investigated the photocatalytic activity of ZnO, Mg-ZnO, and S-ZnO samples with and without PVP mixed with 5 ppm Rhodamine 6G dye at room temperature. Results indicated that pure ZnO nanoparticles have the highest photocatalytic degradation rate with Rh 6G in both situations. The enhanced visible white light photocatalytic activities of pure ZnO NPs were attributed to their superior surface properties (18.30 m2/g) and effective electron-hole separation.