Electrochemical Properties of GaCl₃ in Ionic Liquid [C₂mim][GaCl₄]

Abstract:

Under dry argon atmosphere, the colourless and transparent ionic liquid [C₂mim][GaCl₄] was synthesized. Using [C2mim][GaCl₄] as solvent, a solution of GaCl₃ with molarity 5.227×10-3 mol/cm3 was prepared at 303.15 K and there is a equilibrum between the solute and the solvent: GaCl₃ + [C₂mim][GaCl₄] → [C₂mim][Ga₂Cl₇]. The cyclic voltammogram of the solution had been carried out relative to Al/Al³⁺ reference electrode, with GC working electrode and Ga counter electrode, with various scan rates from 30 to 700mV/s, in a temperature range of 303.15 to 343.15 K, respectively. The results indicated that (1) there were two processes: Ga(Ⅲ)→Ga(I)→Ga(0), which corresponded to the double reduction peaks in the cyclic voltammogram; (2) the first reduction process was a diffusion controlled and quasi-reversible process. Plotting current density of the peak vs the square root of scan rate, a series of straight lines were obtained, then the diffusion coefficients were obtained according to Randles-Sevcik equation in various temperature. The values of diffusion coefficient were fitted to Arrhenius equation with least-square method and value of diffusion activation energy, ED = 41.5 kJ/mol, was obtained from Arrhenius slope.

• Periodical: Advanced Materials Research (Volumes 634-638)
• Pages: 2596-2599
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.634-638.2596
• Online since: January 2013
• Authors: Yi Jin
• Keywords: Cyclic Voltammetry (CV), Diffusion Coefficient, GaCl₃, Ionic Liquid (IL)

References

[1] R.D. Rogers, K.R. Seddon: Ionic liquids Industrial applications for green chemistry (American Chemical Society, Washington DC 2002).

[2] Y. Xie, Z. Zhang, T. Jiang, J. He, B. Han, T. Wu, K. Ding: Angew. Chem. Vol. 119 (2007), p.7393.

[3] F. Endure: CHEMPHYSCHEM, Vol. 3 (2002), p.144.

[4] W.V. Mark, M.K. Carpenter: AIChE Journal Vol. 36 (1990), p.1097.

[5] J.Z. Yang, Y. Jin, W.G. Xu, Q.G. Zhang, S.L. Zang: Fluid Phase Equilibria Vol. 227 (2005), p.41.

[6] J.Z. Yang, P. Tian, L.L. He: Fluid Phase Equilibria Vol. 204 (2003), p.295.

[7] M.K. Carpenter, M. W Verbrugge: J. Electrochem. Soc. Vol. 137 (1990), p.123.

[8] P.Y. Chen, Y.F. Lin, I.W. Sun: J. Electrochem. Soc. Vol. 146 (1999), p.3290.

[9] S.Z. Duan, Z.Y. Qiao: Molten Salt Chemistry―Principle and Application (Metallurgical Industry Press, Beijing 1990).