Optimization of the catalytic activity of manganese dioxide (MnO 2 ) nanoparticles for degradation of environmental pollutants

A routine release of slow-degrading agrochemicals in the environment has resulted in their gradual accumulation posing a major threat both to the terrestrial and aquatic environments worldwide. Robust remediation of such chemicals without causing any further environmental hazard is a highly desirable solution. In this context, we explored the catalytic activity of MnO 2 nanoparticles for the degradation of varieties of commonly used agrochemicals including halogenated aromatic compounds (HACs) under organic solvent-free environmental conditions. The dye Rhodamine B was used as a model compound to optimize degradation. Efficient degradation of RhB was observed at or below pH 5.0 in the 10.0 mM sodium acetate buffer at 25 °C. Degradation efficiency was not affected by light, and MnO 2 nanoparticles could be recycled up to three times without a significant loss of catalytic activity. The catalyst was also capable of degrading a panel of structurally diverse HACs under buffered acidic conditions. The catalytic activities were inhibited by varieties of organic solvents in a concentration-dependent manner. The results provided herein offer a viable option for the timely remediation of varieties of organic pollutants in an environment-friendly manner.