Charge storage mechanism of nanostructured anhydrous and hydrous ruthenium-based oxides

Abstract

The charge storage mechanism of nanostructured anhydrous and hydrous ruthenium-based oxides was evaluated by various electrochemical techniques (cyclic voltammety, hydrodynamic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy). The effects of various factors, such as particle size, hydrous state, and structure, on the pseudocapacitive property were characterized. The electric double layer capacitance (C dl), adsorption related charge (C ad), and the irreversible redox related charge (C irr) per unit mass and surface area of electrode material has been estimated and the role of structural water within the material either in micropores or interlayer are discussed.

Effects of the Electrodeposition Time in the Synthesis of Carbon-Supported Pt(Cu) and Pt-Ru(Cu) Core-Shell Electrocatalysts for Polymer Electrolye Fuel Cells

“…The ligand effect of Cu has also been argued to explain the superior activity of Pt-Cu for oxygen reduction [26]. In the present paper, the positive results can be assigned not only to the electronic effect of Cu but also to the positive effect of the deposited Ru species, which are easily hydroxylated and allow enhancing the CO oxidation due to the bifunctional mechanism [7,35,36,41]:…”

“…Note that the anodic and cathodic currents for Pt-Ru(Cu)/C in the potential region between 0.3 and 0.55 V, related to the double layer charge, were relatively greater than for Pt(Cu)/C. This can be explained by the pseudocapacitive behavior related to the hydroxylation of the Ru species [34,35].…”

Effect of Adding CeO2 to RuO2–IrO2 Mixed Nanocatalysts: Activity towards the Oxygen Evolution Reaction and Stability in Acidic Media

“…The specifics urface area of ruthenium oxide is smaller than that of iridium oxide for materials calcined at 400 8C, as already mentioned in the literature. [24,25] It can be seen in Ta ble 1t hat the increasing amount of cerium as at hird metallic oxide in the RuO 2 -IrO 2 structure increases the specific surface, although the crystallite size of the RuO 2 /IrO 2 phase also increases. These results may be explained by the CeO 2 phase contribution in the oxide material, as the crystallite size of this phase is very small.…”

Towards Implantable Bio-Supercapacitors: Pseudocapacitance of Ruthenium Oxide Nanoparticles and Nanosheets in Acids, Buffered Solutions, and Bioelectrolytes

“…The E 1/2 = 0.60 V vs RHE in H 2 SO 4 is also attributed to reaction 1. 16 Note that if we take differential capacitance that is mostly scan-rate independent in H 2 SO 4 as the C dl (which is often practiced in literature (see for example ref [27,28])), C dl can be estimated as 500 F g −1 . The probe value of 80 μF cm −2 is often used as a measure of the specific capacitance in H 2 SO 4 , which originates from the above mentioned treatment.…”