Abstract

In this study, pure cobalt oxide (Co3O4) as well as nickel cobaltite (NiCo2O4) were investigated with their ca-pacity of degradation efficiency for textile dyes like methyl orange (MO) employing visible light irradiation. Two variable concentrations of nickel cobaltite (NiCo2O4) with 75:25 and 50:50 wt ratios along with the pure metal oxides were synthesized by thermal decomposition method and analyzed by various sophisticated instruments. Initially, the structural characteristics described the fine crystalline nature of NiCo2O4 and also exhibits reduced size than the pure component material (Co3O4). Besides, NiCo2O4 catalysts represented nano cubic shaped particles, and also their coordinating functional groups were evaluated. Further, the absorption wavelength confirms the two band positions of NiCo2O4 which leads to promote visible light absorption, and degrading efficiency of about 47.5% for NiCo2O4 (75:25) sample compared with NiCo2O4 (50:50) which produced only 26.3% degradation. This higher efficiency of the former was due to high crystallinity and interfacial charge transfer of combined Ni2+, Ni3+, Co2+ and Co3+ redox couples. This consecutively produces effective OH radicals that brought the degradation effectively under visible light. The recycling capacity up to 5 repeated cycles has been studied with the NiCo2O4 (75:25) and therefore the catalyst can further be used in other dye degradation.