Photocatalysis has been emerged as a potential solution for the degradation of organic compounds present in wastewater. Zinc oxide (ZnO) possess broad band gap (3.2 eV) absorbing more light quanta to be effective for degradation of organic pollutants. In present work, pure ZnO nanoparticles were synthesized by precipitation method involving dropwise addition and instant addition of zinc acetate dihydrate solution in sodium bicarbonate at different temperature. Alkaline earth metal magnesium (Mg) and transition metal manganese (Mn) were doped with pure ZnO nanoparticles to enhance the photocatalytic degradation rate. The characterization of synthesized nanocatalyst was carried out using XRD, FE-SEM and FTIR. The degradation performance of methyl orange (MO) in the presence of pure ZnO, Mg-ZnO and Mn-ZnO nanocatalyst were carried out in batch reactor by UV irradiation. Degradation efficiency of 90.2% and 85.8% were observed for Mg-ZnO and Mn-ZnO nanocatalyst at neutral pH, 150 mg of catalyst loading and 1000 ppm MO concentration, respectively.