Preparation of Ag-Nanoparticle-Loaded MnO2 Nanosheets and Their Capacitance Behavior

Silver-loaded manganese oxide nanosheets have been prepared by a reassembling reaction between Ag+ ions and delaminated manganese oxide nanosheets, followed by a reduction treatment. The morphologies and structures of the obtained materials are examined by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The reassembling process of the manganese oxide nanosheets is effectively prevented, and manganese oxide nanosheets exist in a complete exfoliation state in Ag-loaded manganese oxide nanosheets. Ag nanoparticles with a size of about 5 nm are highly monodispersed on the manganese oxide nanosheets without agglomeration. The electrochemical properties are characterized by cyclic voltammetry and electrochemical impedance spectroscopy in a 1 mol L-1 Na2SO4 electrolyte. The Ag-loaded manganese oxide nanosheet electrode shows a characteristic Faradic capacitance behavior, and the specific capacitance value is 272 F g(-1) at a scan rate of 10 mV s(-1), much higher than that of the manganese oxide nanosheet electrode (90 F g(-1)). The introduction of Ag nanoparticles into the manganese oxide nanosheet electrode can significantly improve the electrical performance because of the increase in conductivity.