Enhanced photocatalytic degradation property of surfactant-free cobalt oxide nanocapsules on methylene blue dye

The transition metal oxides are emerging materials in solving existing environmental problems of removal of organic dye from the industrial wastes. Out of many transition metal oxides, cobalt oxide is one such potential material of low cost, eco-friendly and easily separable. Herein a facile synthesis route has been adopted for the preparation of Co3O4 nanoparticles which exhibited a best photocatalytic degradation activity. The structure, morphology and optical behaviours were studied using XRD, SEM, UV–Vis and Raman spectra. The photo-degradation of methylene blue on Co3O4 nanoparticles was carried out in the presence of ultra violet light irradiation. The examined results showed the best photocatalytic degradation activity of methylene blue with degradation efficiency of 99.33% in 90 min and rate constant of 0.064. This might be attributed due to enhanced charge separation - transfer and the creation of OH radicals under uv radiation. In addition the Co3O4 nanoparticles are easily separated by using an external magnetic field.