Facile synthesis of MnCO3 nanoparticles by supercritical CO2 and their conversion to manganese oxide for supercapacitor electrode materials

摘要

Spherical manganese carbonate (MnCO3) nanoparticles were prepared from manganese acetate by means of supercritical carbon dioxide (scCO2). The variation of morphology according to temperature, pressure, and solvent composition was studied. Quite uniformly sized MnCO3 nanoparticles were effectively produced in a short period of time with the aid of supercritical fluid. Furthermore, porous manganese oxide (MnOx) nanoparticles with high surface area were obtained via calcination process of MnCO3 nanoparticles, and its performance as a supercapacitor was investigated. The porous manganese oxide nanoparticles showed a high specific capacitance of 322 Fg−1 at 1 Ag−1 with excellent rate capability and cyclic stability. This study provides a new approach for the facile and eco-friendly fabrication of MnCO3 nanoparticles using scCO2 and their conversion to porous MnOx for supercapacitor application.