Synthesis, structure and capacitive properties of cobalt hydroxide films on stainless steel substrates

Abstract

Cobalt (hydro)oxide films on AISI 304 stainless steel and sintered metal fibre filter Bekipor ST 20AL3 were prepared using electrochemical deposition from neutral cobalt acetate solutions under galvanostatic conditions. Deposited films were structurally characterized using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. All electrochemical measurements were performed in aqueous NaOH solution. Capacitive behavior of different films was evaluated using cyclic voltammetry data. The highest specific capacitance (965 F g−1) was reached when Bekipor ST 20AL3 mesh was used as a support for electroactive substance.

Electrocatalytic and pseudocapacitive properties of cobalt (hydro)oxide films on sintered metal fiber filter

“…3a) was measured using the same ferro-ferricyanide oxidation-reduction system. Cobalt oxide Co 3 O 4 , as well-known material for its electrocatalytic activity [6,8,13,[33][34][35] in oxygen evolution reaction, was obtained during heat treatment of as-deposited Co(OH) 2 coatings at 673 K for 1 h. The lamellar structure and composition of tricobalt tetraoxide was confirmed in previous studies [23] by XRD, FTIR and XPS. In order to investigate the effect of temperature treatment to electroactive surface area, the same measurements as with Co(OH) 2 were performed (Fig.…”

“…The electrodeposition process was carried out under galvanostatic conditions. The previously obtained results [23] showed that the most stable films were obtained at 0.5 mA/cm 2 . Temperature treatment for all deposited coatings was carried out in 673 K for 1 h; temperature raising speed was 10 K min…”

“…The lamellar structure and composition of a-Co(OH) 2 of asdeposited films were confirmed by XRD, FTIR and XPS [23].…”

“…As it has been mentioned previously [23], the losses of the specific capacitance were calculated to be around 50-60% for the first cycle and 1-3% for all the other cycles for asdeposited coatings. Meanwhile, annealed coatings distinguish with much better stability: the losses of specific capacitance do not exceed 4%.…”

“…Structure and morphology of the films Previous studies [23] showed that the most stable films are deposited at the current density of 0.5 mA/cm 2 . The lamellar structure and composition of a-Co(OH) 2 of asdeposited films were confirmed by XRD, FTIR and XPS [23].…”