Silver Nanoparticles-Decorating Manganese Oxide Hybrid Nanostructures for Supercapacitor Applications.

A facile aerosol-based synthetic approach is demonstrated for the fabrication of silver-manganese oxide (Ag-MnOx) and cetyltrimethylammonium bromide (CTAB)-templated silver-manganese oxide (c-Ag-MnOx) hybrid nanostructures as the positive electrode materials of supercapacitors. Through gas-phase evaporation-induced self-assembly, silver nanoparticles are homogeneously decorated in the hybrid nanostructure to create a conductive path at the interface of the cluster of MnOx crystallites. The utilization of the capacitance of MnOx increases by the addition of Ag nanoparticles (>2 times for Ag-MnOx and ∼1.7 times for c-Ag-MnOx). An optimal specific capacitance is achieved when the concentration of the silver precursor (CAg) is 0.5 wt %, 118 F g-1 for Ag-MnOx, and 154 F g-1 for c-Ag-MnOx at a specific current of 1 A g-1. The enhanced supercapacitive performance by the addition of CTAB at low CAg is attributed to the increased surface area (>19.4%) for electrochemical reactions. The prototype method with mechanistic understanding demonstrated in this study shows promise for the fabrication of a variety of MnOx-based hybrid nanostructures for supercapacitor applications.