Morphology and Electrochemistry of Ruthenium/Carbon Aerogel Nanostructures

Abstract

The structure−property relationships of nanostructured Ru/carbon aerogel composite materials have been evaluated. These new materials were prepared via a novel two-step metal vapor impregnation method which enables one to control the Ru loading through repetition of the process. The resulting microstructure is characterized by highly dispersed Ru particles (≈20−30 Å in diameter) attached to the carbon aerogel surface and distributed homogeneously throughout the material; the open pore structure of the carbon aerogels remains largely unaffected. Electrochemical characterization indicates that it is possible to increase the specific capacitance of the carbon aerogels in 1.0 M H2SO4 from ≈100 F/g to greater than 250 F/g for samples with >50 wt % Ru due to the pseudocapacitive properties of hydrous RuO2. A volumetric capacitance greater than 140 F/cm3 was observed for some samples. In addition, these materials show good cycling characteristics. Electrochemical impedance spectroscopy was unable to distinguish between double-layer capacitance and pseudocapacitance in these materials.

Recent Progress in the Synthesis of Porous Carbon Materials

“…[26] A ruthenium/carbon aerogel composite was prepared via a novel two-step metal-vapor-impregnation method. [27] The resulting composite had highly dispersed Ru particles attached to the carbon aerogel and was used as the electrode material for supercapacitors. Capacitances greater than 250 F g -1 were obtained for the samples with 50 wt % Ru and the capacitance of these composites could be tailored by varying the Ru loading and/or the density of the host carbon aerogel.…”

A Novel Approach Towards Carbon–Ru Electrodes with Mesoporosity for Supercapacitors

“…[16][17][18][19][20] These composites increase effectively the specific capacitance and improve the rate performance compared to pure porous carbon. [17][18] However, the so far reported methods reveal several drawbacks associated with the incorporation of Ru or RuO 2 into a carbon matrix, as for example the low control over the size and dispersion of the nanoparticles and the complicated procedures of loading Ru nanoparticles on the carbon support. [19][20] Herein, we report a novel approach for the formation of carbon-Ru composites with Ru nanoparticles homogeneously dispersed in a highly porous carbon matrix.…”

Electrode Materials with Pseudocapacitive Properties

“…However, the cost, lack of abundance, and toxic character necessitate seeking alternative materials. Hence, great attention has been devoted to manganese oxide, especially because of its environmentally friendly character [41][42][43][44][45][46][47][48][49][50][51][52].…”