Electrodeposition of cobalt from aqueous sulphate solutions in the presence of tetra ethyl ammonium bromide

Electrochemical Nucleation and Growth of Cobalt from Methanesulfonic Acid Electrolyte

“…9 In the fabrication of cobalt and cobalt alloys, electrodeposition is always considered as an effective and efficient way as the coating composition and structure can be conveniently controlled by varying the operating conditions, for instance, the current density. Up to date, cobalt has been electrodeposited from chloride, 1,2,10-12 sulfate 13 and citrate [14][15][16] aqueous baths as well as from the urea-choline chloride-CoCl 2 melt 17 and deep eutectic solvent, 18 the influence of deposition parameters on current efficiency, 12 deposit morphology, 19 structure 20 and magnetic properties 19,21,22 was also investigated. With respect to the electrocrystallization mechanism, the influence of many factors such as cobalt concentration, 2 pH, 23,24 temperature, 25 substrate [26][27][28] and ultrasound 29 on the nucleation and growth of cobalt has been reported in previous studies, however, it should be emphasized here that most researches were performed in weakly-acidic and dilute solution, only the work performed at high pH by Grujicic and Pesic 23 and the work performed in concentrated solution by Bertazzoli et al 24 were noted as an exception, no research on the electrocrystallization mechanism from strongly-acidic and concentrated solution has been documented.…”

Study of the electrochemical recovery of cobalt from spent cemented carbide

“…The cobalt in spent cemented carbides, the deposition potential and the deposition current in deionized water, and the reduction process on the cathode surface were studied with linear sweep voltammetry testing. 12,13 The temperature was 298 K. The linear sweep voltage range was À0.15 to À1.70 V. The scan range was 100-115 mV s À1 . The test results are shown in Fig.…”

Green production of hydrogen-doped faceted cobalt microcrystals using water-assisted molten salt electro-reduction method

“…These methods can mainly be divided into two categories. The methods in the first category are based on the electrodeposition of cobalt from aqueous solutions such as acidic CoSO 4 Á7H 2 O-Na 2 SO 4 in the presence of tetraethylammonium bromide, 23 or non-aqueous low-temperature electrolytes containing electroactive soluble Co species such as CoCl 2 in urea acetamide-LiBr 24 or Co(TFSA) 2 in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide in the presence of coumarin and thiourea. 25 Unfortunately, the application of these lowtemperature electrolytic methods is restricted due to the expensive and environmentally problematic reagents involved, and also the low kinetics of the processes conducted at low temperatures, as well as the low quality of the deposited cobalt.…”