Influence of atmospheric water uptake on the hydrolysis of stannous chloride in the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate

In this paper we report on the influence of water uptake on the hydrolysis of anhydrous stannous chloride in the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate ([Py1,4]TfO) under ambient atmosphere. The effect of water uptake on the electrodeposition of tin in the employed ionic liquid containing 0.1 M SnCl2 was also demonstrated. The hydrolysis products as well as the Sn electrodeposits were characterized by different techniques comprising; scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results show that the employed ionic liquid electrolyte strongly absorbs water under ambient conditions. Colloidal particles were formed in the electrolyte after an exposure time of about 4 weeks as a result of the hydrolysis of Sn(II) species. The electrochemical behaviour of the employed electrolyte and the morphology of tin electrodeposits were significantly influenced by the presence of water. Tin dendrites were obtained from IL-electrolyte exposed to air for one month, whereas dendrite free deposits were formed in the freshly prepared electrolyte.