Effect of operational parameters on the photocatalytic degradation of Methylene blue dye solution using manganese doped ZnO nanoparticles

Photocatalytic degradation of aqueous solution of methylene blue dye under UV light illumination was studied by using manganese doped ZnO (Zn1-xMnxO, where x = 0.00, x = 0.02 and x = 0.05) nanoparticles as a photocatalyst. The nanophotocatalysts were synthesized by wet chemical co-precipitation method. The structural, morphological, and optical properties of the photocatalysts were done by X-ray diffraction (XRD), Scanning Electron microscope (SEM), Energy Dispersive X-Ray (EDX), photoluminescence (PL), Fourier Transform Infrared Ray (FTIR) and UV-visible spectroscopic techniques. An improved photocatalytic efficiency of ZnO was observed upon doping with Mn and 2% Mn-doped ZnO exhibited the highest photocatalytic activity among the doped samples. The effect of operating parameters such as amount of catalyst, the initial dye concentration, and initial pH on the rate of dye degradation using 2% Mn-doped ZnO was studied. Under the optimum operation conditions, approximately 99% of dye removal was achieved after 120 min of irradiation.