Electrochemical behavior of tantalum ions in molten salt electrolysis for nano-powder preparation

Abstract

This research focused on analyzing the electrochemical properties of tantalum ions in NaCl-KCl molten salt during the extraction of tantalum and the synthesis of tantalum nano-powder. Tantalum ions were dissolved from the anode. Linear sweep voltammetry, cyclic voltammetry, square wave voltammetry, and chronoamperometry were employed to delve into the reduction and diffusion processes of tantalum ions. The study determined the diffusion coefficient, the nucleation process, and the deposition potential for tantalum ions. The findings revealed that the electrode reduction process of tantalum ions involved a three-step reaction: Ta5+→Ta3+→Ta+→Ta. This reaction was shown to be reversible and diffusion-controlled. The nucleation mode of tantalum ions was identified as instantaneous nucleation followed by progressive nucleation as the potential increased by chronoamperometry analysis. The cathodic deposition product was characterized using XRD, SEM, EDS, and TEM techniques, confirming the nanoscale granular nature and microstructure of the deposition products.