Highly active MnO2 nanosheet synthesis from graphene oxide templates and their application in efficient oxidative degradation of methylene blue

In this paper, a facile one-step method towards manganese oxide nanosheets is described which uses graphene oxide as a self-sacrificial template. A redox reaction between graphene oxide nanosheets and KMnO4 results in the formation of few-layer MnO2 nanosheets due to the in situ replacement of the carbon framework by edge-sharing [MnO6] octahedra. It is also demonstrated that these MnO2 nanosheets show high activity for the oxidative degradation of methylene blue (MB) dye, in which the MB dye can be decomposed into small molecule fragments through fast demethylation, followed by aromatic ring cracking, and partial mineralization into inorganic ions in a short time. We expect that the few-layer MnO2 nanosheets may be envisaged as a new non-toxic material for the treatment of organic dye-containing wastewater, and its application for the oxidation of other organic pollutants in environmental pollution cleanup.