Coating MnO2 nanowires by silver nanoparticles for an improvement of capacitance performance

Abstract MnO 2 nanowire/Ag nanoparticles composites for supercapacitor were synthesized with a two-step procedure, which involves preparing MnO 2 nanowires and acquiring conductive Ag nanoparticles grown on the surface of MnO 2 nanowires with reducing Ag + . The results show that Ag nanoparticles are not only to improve the electric conductivity, but also to enhance the structural stability of the composites. The composites have an excellent specific capacitance of 396.4 F/g at a scan rate of 50 mV/s in 1 M Na 2 SO 4 aqueous solution, which is almost five times that of the pure MnO 2 nanowires. Besides, capacitance retention of 95.2% for the MnO 2 /Ag over 2000 charge/discharge cycles at a charge/discharge current of 5 A/g is much better than that of the pure MnO 2 NWs.