Optimization of the catalytic activity of manganese dioxide (MnO2) 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 MnO2 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 MnO2 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. [ABSTRACT FROM AUTHOR]