Highly porous carbon materials filled with gold and manganese oxide nanoparticles for electrochemical use
•Synthesis of chemically pure and spatially regular formed nanocomposites.•Controllable modification of shape and size characteristics of filling particles.•Improving the electrochemical characteristics of nanocomposite electrodes.
The reduction of aqueous solutions of precursors (HAuCl4 and KMnO4) by the carbon matrix was used to synthesize nanostructured composites based on highly porous carbon materials that are filled with Au or MnxOy nanoparticles. The resulting composites were characterized using a complex of complementary physicochemical methods (XRD, SAXS, low-temperature nitrogen sorptometry, and CV). It was shown that at low concentrations of Au or MnxOy the surface of matrix pores is decorated with the filler nanoparticles, which block mesopores; the role of such blocking increases with the filler content. The optimal concentration of fillers in the composites was found. A maximum capacitance of composite electrodes, which exceeds the capacitance of electrodes based on the initial matrices by a factor of 2–2.5, was observed at a gold content of 1 wt.%. Nanocomposite Au/C electrodes based on highly porous carbon material Kemerit2, which were obtained in the study, showed the highest capacitance (up to 1000 F/g). For the composite systems filled with manganese oxides, a 700 F/g capacitance of composite electrodes (at a 10 mV/s scanning rate of potential) was reached at a 2 wt.% content of manganese in the composites.
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Journal: Catalysis Today - Volume 249, 1 July 2015, Pages 220–227