Preparation of Co-Ni Oxide/Vertically Aligned Carbon Nanotube and Their Electrochemical Performance in Supercapacitors

Abstract

A Co-Ni oxide/vertically aligned carbon nanotube (VACNT) composite was prepared by thermal decomposition of cobalt-nickel nitrate precursor on the surface of VACNT electrode. VACNTs were used as 3D nanoporous substrate and were grown by plasma enhanced chemical vapor deposition from a mixture of H 2 and C 2 H 2 . The specific capacitance of Co-Ni oxide (5:5)/VACNT (with equal Co +2 /Ni +2 mole ratio) was measured to be 1050 Fg −1 which is about 1.9-and 3-fold that of Ni oxide/VACNT (540 Fg −1 ) and Co oxide/VACNT (341 Fg −1 ), respectively. The results show Co-Ni oxide (5:5)/VACNT composite electrode has excellent specific capacitance because of porous network structure, good electrical conduction pathways, high access for the electrolyte solution, and consequently increased composite/solution interfacial contact area. The capacitance property of the Co-Ni oxide/VACNT composite electrode with different Co +2 /Ni +2 mole ratios was also investigated and the highest specific capacitance is achieved at equal Co +2 /Ni +2 mole ratio. Downloaded by [Istanbul Universitesi Kutuphane ve Dok]

Nitrogen-Doped, Vertically Aligned Structures of Graphene and Carbon Nanofibers for Energy Storage Applications

“…The generation of nanosized particles during the PECVD could be explained in two possible ways. One suggests the formation of semispherical Ni islands on the Ni facets to minimize their high surface energy. , Another possibility is the sputtering and redeposition of Ni nanoparticles by plasma species resulting from the decomposition of NH 3 and C 2 H 2 , similar to what was reported in refs , . In our DC-PECVD reactor environment, the substrate serves as a cathode, and positively charged ion bombardment may occur, which could lead to Ni catalyst sputtering.…”

“…One suggests the formation of semispherical Ni islands on the Ni facets to minimize their high surface energy. 49,50 Another possibility is the sputtering and redeposition of Ni nanoparticles by plasma species resulting from the decomposition of NH energy, followed by 100 and 111, may contribute to the selective attachment of the sputtered nanosized Ni particles. 52 This phenomenon enables the reduction of the surface energy of the high-energy facets, thus bringing them into a thermodynamically stable state.…”

Influence of pulse operational parameters on pure nickel electrodeposits: Part II. Microhardness and corrosion resistance

“…1 One of the main advantages of employing nickel coatings is its tendency to passivation, significantly improving corrosion resistance of nickel in several media such as water, alkali, organic and mineral acids. 2,3 The protective properties of nickel electrodeposits with respect to different substrates or undercoats such as Cu are often satisfactory. 4 If nickel electrodeposit is employed for corrosion protection of a metallic substrate, the porosity of the nickel plate and its corrosion resistance provided by the Ni deposit itself are very important.…”

Structural Investigation of Catalytically Grown Carbon Nanotubes

“…The common methods for the synthesis of CNTs include arc discharge, laser ablation, chemical vapour deposition and thermal decomposition of hydrocarbons [4][5][6]. Most of these methods use transition metal/oxides and some organometallic complexes as catalysts [6,7]. However, all of these methods involve high-power consumption because of the high temperatures employed.…”