An Environmentally Friendly Synthesis of Mn-doped ZnO Nanoparticles and its Enhanced Antibacterial, Electrochemical and Photocatalytic behaviors: Effect of Doping Concentration

Mn-doped ZnO nanoparticles are prepared using orange peel extract and the samples are annealed at 500 degrees C. The structural, morphological and optical properties are examined as a function of doping concentration. The Debye-Scherrer's formula, Williamson-Hall equation and Halder-Wagner method are employed to explore the crystallite size of the prepared nanoparticles. The defects of the nanoparticles are enhanced due to the addition of the dopant. The hole concentration is about 4 times greater than the electron concentration. The nanoparticles are positive-type and show the red-shifted band gap as the doping concentration of Mn increases. The enhanced zone of inhibition is observed against Bacillus subtilus, Staphylococcus aureus and Klepsiella pneumonia due to doping. A high specific capacitance of similar to 600 F/g is observed which corresponds to the 2% Mn-doped nanoparticles. Mn-doped ZnO nanoparticles have excellent photocatalytic activity against methyl orange dye and have the degradation efficiency of 92% in 80 min under visible light.