Effect of the Co[sub 3]O[sub 4] Introduction in the Pseudocapacitive Behavior of IrO[sub 2]-Based Electrode

Abstract

A new electrode based on IrO 2 ϩ Co 3 O 4 ͑30:70 mol %͒ composition has been prepared by thermal decomposition ͑400°C͒ from mixtures of chloride precursors and characterized by energy dispersive X-ray, scanning electron microscopy, X-ray diffraction analysis, cyclic voltammetry, and charging/discharging curves. The electrochemical behavior shows dependence on the cathodic potential limit employed, and a good potential window ͑1.4 V͒ in aqueous NaOH and high electrocatalytic area due to the contribution of different redox transitions of Ir and Co surface sites. The electrode has been found to perform as superior electrodes in electrochemical capacitor applications with a specific capacitance of 500-600 F g Ϫ1 . The large capacitance exhibited by this system arises from a combination of the double layer capacitance and pseudocapacitance associated with surface redoxtype reactions.

Electrochromism of amorphous ruthenium oxide thin films

“…An electrochemical capacitor of large specific capacitance (supercapacitor) results when an electrode material with large specific surface area is combined with a material that can be reversibly oxidized or reduced over a wide potential range. For example, the oxides of multivalent metals such as ruthenium and iridium exhibit large faradaic pseudocapacitance [4][5][6]. Consequently, these materials have often been studied for applications as supercapacitors.…”

Stable spinel type cobalt and copper oxide electrodes for O2 and H2 evolutions in alkaline solution

“…Since the electrode undergoes negative and positive polarization, the CV curves shown in Fig. 4 are different from those reported results where only positive polarization were studied [12,13,20,24]. The electrochemical behavior of Cobalt in alkaline solution is very complicated as discussed in detail by Gomez Meier et al [27].…”

“…DSAs with spinel structure, especially for cobalt spinel oxides, are receiving considerable attention due to their inexpensive cost, long service life in alkaline solution and high electrocatalytic properties [9][10][11][12][13]. In addition, this kind of material also has good corrosion resistance and the possibility to be a good catalyst toward complex electrochemical reactions [14].…”

Effect of Pt nanostructures on the electrochemical properties of Co3O4 electrodes for micro-electrochemical capacitors

“…[12]. To enhance its electrochemical performance, some groups combined Co-oxides with oxide-and/or carbon-based materials [13][14][15]. For example, Grupioni and Lassali [13] synthesized Co 3 O 4 electrode combined with IrO 2 (30 mol%) by thermal deposition and reported specific capacitance of 500-600 F/g.…”

“…To enhance its electrochemical performance, some groups combined Co-oxides with oxide-and/or carbon-based materials [13][14][15]. For example, Grupioni and Lassali [13] synthesized Co 3 O 4 electrode combined with IrO 2 (30 mol%) by thermal deposition and reported specific capacitance of 500-600 F/g. Shan et al [14] fabricated pseudo-capacitors using multi-wall (MW) CNTs/Co 3 O 4 composite electrodes, which were prepared by acid treatment of MWCNTs and Co(NO 3 ) 2 in an n-hexanal solution and reported specific capacitance of ∼200 F/g.…”