Indirect Transformation of Coordination-Polymer Particles into Magnetic Carbon-Coated Mn3O4 (Mn3O4@C) Nanowires for Supercapacitor Electrodes with Good Cycling Performance

Carbon-coated Mn3O4 nanowires (Mn3O4@C NWs) have been synthesized by the reduction of well-shaped carbon-coated bixbyite networks and characterized by TEM, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical experiments. To assess the properties of 1D carbon-coated nanowires for their use in supercapacitors, cyclic voltammetry and galvanostatic chargingdischarging measurements were performed. Mn3O4@C NWs could be charged and discharged faster and had higher capacitance than bare Mn3O4 nanostructures and other commercial materials. The capacitance of the Mn3O4@C NWs was 92% retained after 3000cycles at a charging rate of 5Ag1. This improvement can be attributed to the carbon shells, which promote fast Faradaic charging and discharging of the interior Mn3O4 core and also act as barriers to protect the inner core. These Mn3O4@C NWs could be a promising candidate material for high-capacity, low-cost, and environmentally friendly electrodes for supercapacitors. In addition, the magnetic properties of the as-synthesized samples are also reported to investigate the influence of the carbon coating.