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-MnO) and cetyltrimethylammonium bromide (CTAB)-templated silver-manganese oxide (c-Ag-MnO) 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 MnO crystallites. The utilization of the capacitance of MnO increases by the addition of Ag nanoparticles (>2 times for Ag-MnO and ∼1.7 times for c-Ag-MnO). An optimal specific capacitance is achieved when the concentration of the silver precursor (C_Ag) is 0.5 wt %, 118 F g^-1 for Ag-MnO, and 154 F g^-1 for c-Ag-MnO at a specific current of 1 A g^-1. The enhanced supercapacitive performance by the addition of CTAB at low C_Ag 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 MnO-based hybrid nanostructures for supercapacitor applications.