Electrodeposition of tungsten from EMPyrCl-ZnCl₂ melts at 150ºC

Abstract

Electrodeposition of tungsten has been achieved at 150°C, which is the lowest temperature to this day, by using a new molten salt (ionic liquid), N-ethyl-N-methylpyrrolidinium chloride (EMPyrCl)-ZnCl₂. Metallic tungsten was electrodeposited on a nickel substrate by potentiostatic electrolysis at 0.01 V vs. Zn(II)/Zn in an equimolar EMPyrCl-ZnCl₂ melt after adding KF and WCl₄. A denser and smoother tungsten film was obtained by the same electrolysis condition when WCl₆ was used as a tungsten ion source.