Optical and Photocatalytic study of Mn doped ZnS and ZnS/CeO2 nanocomposites

Abstract

The widespread problem of water pollution is threatening our lives. Water pollution kills more people than killed during a war. Due to the shortage of clean drinking water there is a need of wastewater treatment and for this photocatalysis is one of the most effective methods. Transition metal oxides and sulphides are mostly used semiconductor photocatalysts out of which wide band gap semiconductor ZnS having similar physical properties with that of intensively studied ZnO can also be used effectively. In the present study an attempt is made to increase the photocatalytic application of ZnS by doping (Mn) and coupling it with other semiconductor (CeO2). The undoped and Mn2+ doped ZnS nanoparticles were synthesized using co-precipitation method and then using these nanocomposite samples (ZnS/CeO2) were

prepared by hydrothermal method. Structural and morphological study was carried out by X- ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) techniques. Change in optical properties with doping and coupling of two semiconductors were studied using UV-visible and photoluminescence spectra. The presence of CeO2 and Mn was confirmed by PL spectra and Fourier transformation of infrared spectroscopy (FTIR). To know the effect of Mn and CeO2 on photocatalytic activity of ZnS the degradation of rhodamine B (RhB) dye (1 mg/L) was observed under UV and solar irradiation. The results of photocatalytic reaction has been presented and explained well with the help of PL results in this present investigation.