Study of Photocatalytic Activity of Mn1-xCuxS Nanoparticles

Abstract

Manganese Sulfide (MnS) is a wide band gap (3.7 eV) p-type semiconductor comprising three crystalline (cubic rock-salt MnS, cubic zincblende MnS, and hexagonal wurtzite MnS structures) polymorphs. Pristine and copper-doped MnS nanoparticles have been synthesized using a facile chemical co-precipitation method. Crystallographic, morphological, qualitative, and quantitative characteristics of synthesized Mn1-xCuxS (0 x 0.09) nanoparticles have been studied using X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), and UV-Visible absorption spectroscopy. Recorded diffractograms reveal the formation of a dual crystal phase of MnS as hexagonal wurtzite gamma MnS and cubic rock-salt alpha MnS phase, while FE-SEM analyses indicate the cauliflower morphology of synthesized nanoparticles. The direct band gap energy for Mn1Cu0S NPs and Mn0.91Cu0.09S NPs was calculated to be 3.85 eV and 3.80 eV, respectively. Photocatalytic activity of synthesized nanoparticles has been studied using Rhodamine B (RhB) dye as a test contaminant in aqueous media under UV (UVC; 230 W) irradiation. Mn0.93Cu0.07S NPs exhibited the highest photocatalytic activity with a degradation efficiency of 46.72%. Photocatalytic activity dependence on doping concentration and morphology has been thoroughly studied to explore the potential of synthesized nanoparticles for polluted water purification.