Unusual electrochemical behaviour of AuBr4− in ionic liquids. Towards a simple recovery of gold(iii) after extraction into an ionic liquid

RSC Advances ◽  
2014 ◽  
Vol 4 (103) ◽  
pp. 58910-58915 ◽  
Author(s):  
Nicolas Papaiconomou ◽  
Nicolas Glandut ◽  
Isabelle Billard ◽  
Eric Chainet

The electrochemistry of AuBr4− complexes extracted into ionic liquids [C8PYR][NTf2] or [C8MIM][NTf2] saturated with water and gas has been studied by cyclic voltammetry on a glassy carbon macro electrode and by linear voltammetry on a platinum microelectrode.

2020 ◽  
Vol 73 (11) ◽  
pp. 1080
Author(s):  
Laura Sanchez-Cupido ◽  
Jennifer M. Pringle ◽  
Amal Siriwardana ◽  
Cristina Pozo-Gonzalo ◽  
Maria Forsyth

Electrodeposition using ionic liquids has emerged as an environmentally friendly approach to recover critical metals, such a neodymium. The investigation of ionic liquid chemistries and compositions is an important part of the move towards efficient neodymium recovery from end-of-life products that needs further research. Thus, in this paper we have investigated a series of phosphonium ionic liquids as potential electrolytic media. Anions such as bis(trifluoromethylsulfonyl)imide (TFSI), dicyanamide (DCA), and triflate (TfO) have been investigated, in combination with short- and long-alkyl-chain phosphonium cations. The work here suggests that [TFSI]– is one of the most promising anions for successful deposition of Nd and that water plays an important role. In contrast, electrochemical behaviour was significantly hindered in the case of DCA ionic liquid, most likely owing to strong coordination between [DCA]– and Nd3+. Mixtures of anions, [TfO]– and [TFSI]–, have also been investigated in this work, resulting in two reduction processes that could be related to a different deposition mechanism involving two steps, as observed in the case of dysprosium or, alternatively, different coordination environments that have distinct deposition potentials. Additionally, we investigated the influence of electrode substrates – glassy carbon and copper. Cu electrodes resulted in the largest current densities and thus were used for subsequent electrodeposition at constant potential. These findings are valuable for optimising the deposition of Nd in order to develop more efficient and inexpensive recycling technologies for rare earth metals.


RSC Advances ◽  
2014 ◽  
Vol 4 (17) ◽  
pp. 8431-8438 ◽  
Author(s):  
Sadegh Khazalpour ◽  
Davood Nematollahi

Electrochemical behaviour of resazurin in aqueous buffered solutions and ionic liquid was studied. The orientation of adsorbed resazurin was estimated. It is found that, the orientation of the adsorbed resazurin at glassy carbon surface is edgewise.


2008 ◽  
Vol 5 (3) ◽  
pp. 539-550 ◽  
Author(s):  
Ibrahim Ender Mulazimoglu ◽  
Erdal Ozkan

In this study, cyclic voltammetry and electrochemical ımpedance spectroscopy have been used to investigate the electrochemical behaviour of quercetin (3,3′,4′,5,7-pentahydroxyflavone) on the procaine and aminophenyl modified electrode. The modification of procaine and aminophenyl binded electrode surface with quercetin was performed in +0,3/+2,8 V (for procaine) and +0,4/+1,5 V (for aminophenyl) potential range using 100 mV s-1scanning rate having 10 cycle. A solution of 0.1 M tetrabutylammonium tetrafluoroborate in acetonitrile was used as a non-aquous solvent. For the modification process a solution of 1 mM quercetin in 0.1 M tetrabutylammonium tetrafluoroborate was used. In order to obtain these two surface, a solution of 1 mM procaine and 1 mM nitrophenyl diazonium salt in 0.1 M tetrabutylammonium tetrafluoroborate was used. By using these solutions bare glassy carbon electrode surface was modified. Nitrophenyl was reduced to amine group in 0.1 M HCl medium on the nitrophenyl modified glassy carbon elelctrode surface. Procaine modified glassy carbon electrode surface was quite electroactive. Although nitrophenyl modified glassy carbon elelctrode surface was electroinactive, it was activated by reducing nitro group into amine group. For the characterization of the modified surface 1 mM ferrocene in 0.1 M tetrabutylammonium tetrafluoroborate for cyclic voltammetry and 1 mM ferricyanide/ferrocyanide (1:1) mixture in 0,1 M KCl for electrochemical impedance spectroscopy were used.


2006 ◽  
Vol 94 (3) ◽  
Author(s):  
P. Giridhar ◽  
K. A. Venkatesan ◽  
B. P. Reddy ◽  
T. G. Srinivasan ◽  
P. R. Vasudeva Rao

SummaryRoom temperature molten salts for possible application of recovery of fission palladium from irradiated nuclear fuel/wastes have been investigated. The redox behavior of a solution of palladium(II) chloride and 1-butyl-3-methylimidazolium chloride (bmimCl) at glassy carbon working electrode has been studied at various temperatures using cyclic voltammetry. The voltammogram of bmimCl-PdCl


ChemPhysChem ◽  
2009 ◽  
Vol 10 (17) ◽  
pp. 3090-3096 ◽  
Author(s):  
Essam M. Moustafa ◽  
Olivier Mann ◽  
Wolfram Fürbeth ◽  
Rolf Schuster

2016 ◽  
Vol 18 (11) ◽  
pp. 8148-8157 ◽  
Author(s):  
C. Bonnaud ◽  
I. Billard ◽  
N. Papaiconomou ◽  
E. Chainet ◽  
J. C. Leprêtre

A comparison between quasi-reference and reference electrodes was carried out in ionic liquid media by cyclic voltammetry. The stability and the reliability of these reference electrodes are discussed.


2017 ◽  
Vol 41 (16) ◽  
pp. 7840-7843 ◽  
Author(s):  
I. Chiarotto ◽  
M. Feroci ◽  
A. Inesi

Cyclic voltammetry measurements provide the first direct evidence of N-heterocyclic carbene in neat 1-butyl-3-methylimidazolium acetate ionic liquid at temperatures over 120 °C.


1995 ◽  
Vol 73 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Rajeev Jain ◽  
M. Damodharan

Electrochemical behaviour of the medicinally important 4-(4′-sulphonamoyl)hydrazono-1-phenyl-3-methyl-2-pyrazolin-5-ones has been studied at d.m.e. and glassy carbon electrodes. At d.m.e., all six compounds exhibited a single, well-defined, four-electron wave in the pH range 2.5–12.0. Polarographic four-electron wave was found to be diffusion-controlled and irreversible. Similarly, cyclic voltammetry of these compounds at glassy carbon electrode exhibited a single peak. Peak potential shows shifts towards negative potential with pH, with linear segments up to pH 8.2 and are practically pH independent at higher pH values. An anodic peak at far-off positive potential was observed in the reverse scan, indicating the irreversible nature of the electrode process. Controlled potential electrolysis and coulometric studies gave the value of n as 4.0 ± 0.1 in the pH range 2.5 to 10.0. Out of the two major end products formed, one was identified as sulphanilamide and the other as 1-phenyl-3-methyl-4-amino-2-pyrazolin-5-one on the basis of IR and NMR studies. On the basis of DCP, LSV, CV, CPE, coulometry and spectral analysis, a mechanism has been postulated for the reduction of these compounds at d.m.e. and glassy carbon electrodes. Keywords: polarography, cyclic voltammetry, antibacterials, pyrazolin-5-ones.


2017 ◽  
Vol 68 (9) ◽  
pp. 1963-1968
Author(s):  
Ana Maria Popescu ◽  
Cristina Donath ◽  
Elena Ionela Neacsu ◽  
Vasile Soare ◽  
Ionut Constantin ◽  
...  

The recovery of metals from a multi-component alloy obtained by crushing, melting and anodic dissolution of waste electric and electronic equipment (WEEE) has been investigated. The aim of this paper is to selective recover of Sn, Pb and Zn by a novel ecological technology using ionic liquids. Metallic Sn, Pn and Zn were electrochemically recovered from the WEEE dissolved in choline chloride-ethylene glycol-iodine ionic liquid. Cyclic voltammetry was used in order to determine the deposition potentials of the studied metals. XRD and SEM/EDX analysis methods were used to characterize the structure and morphology of the metallic deposits. Evolution of the cathodic deposition and of the chemical composition of the anode during the anodic dissolution process for Sn, Pb and Zn was also studied. This study has demonstrated the possibility of selective recovery of Sn, Pb and Zn from the multi-component alloy (which resulted from consecutive anodic dissolution of WEEE) by anodic dissolution/deposition in ionic liquids.


2015 ◽  
Vol 39 (2) ◽  
pp. 135-146
Author(s):  
Md Toufiqur Rahman ◽  
Md Uzzal Hossain ◽  
MQ Ehsan

Electrochemical behaviour of catechol, hydroquinone and resorcinol was investigated in KCl, acetate buffer and phosphate buffer at glassy carbon electrod using cyclic voltammetry. The results imply that the glassy carbon electrode exhibited a synergistic and excellent electrocatalytic effect on the redox behaviors of the benzenediols. Catechol and hydroquinone show one pair of redox peaks in acetate and phosphate buffer but two pairs of redox peaks in KCl. In all cases the redox process is quasireversible. Resorcinol behaves almost irreversibly in all three electrolytic media. Good linear relationships were obtained between the peak currents and the concentrations of benzenediols. The electrochemical process in all the isomers was controlled by diffusion process.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 2, 135-146, 2015


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