Electrochemical formation of selenium nanoparticle in an amide-type ionic liquid

Electrochemical formation of selenium (Se) nanoparticles in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing selenium tetrachloride (SeCl₄) was investigated in the presence of excess chloride anion on a glassy carbon electrode. Electrochemical reduction of [SeCl₆]^2- resulted in deposition of Se on the electrode surface. The deposited Se was further reduced electrochemically at the more negative potential region to form [Se₂]^2-, which was suggested to exist by ultraviolet-visible spectroscopy. Se nanoparticles dispersed in the ionic liquid were formed by the proportionation reaction between [SeCl₆]^2- and [Se₂]^2- in the ionic liquid. The Se nanoparticles were characterized by energy dispersive X-ray spectroscopy and transmission electron microscopy.