Electrochemical and Phase Analysis of Si(IV) on Fe Electrode in Molten NaCl-NaF-KCl-SiO2 System

High Temperature Materials and Processes

Reddy Ramana G.¹  Xie Shanshan²  Liang Jinglong²  Wang Lanqing²  Li Hui² 

[1] Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL35487, USA;Key Laboratory of Ministry of Education for Modern Metallurgy Technology, College of Metallurgy and Energy, North China University of Science and Technology, Tangshan063210, China;

关键词: cyclic voltammetry;    square wave voltammetry;    chronoamperometry;    chronopotentiometry;    compound systems;   

DOI  :  10.1515/htmp-2017-0113

来源: DOAJ

【 摘 要 】

The electrochemical behaviour of Si(IV) ions on Fe electrode in the NaCl-NaF-KCl-SiO2 molten salt system (0.177 mol·L−1 SiO2) at 1,103 K was studied by using cyclic voltammetry, square wave voltammetry, chronoamperometry, and chronopotentiometry．Experiments conducted using the first two methods indicated that the reduction of Si(IV) occurred in two steps: Si(IV) → Si(II) → Si(0). Furthermore, the electrochemical reaction is a quasi-reversible process, which is controlled by both the ion diffusion and electron transport rates. The electrochemical crystallization of Si was found to be a transient, the three-dimensional nucleation process. The cyclic voltammetry curves indicate that the diffusion coefficient of Si(IV) is 1.16×10–5 cm2·s−1. The phases formed on the surface of the deposit were analysed by scanning electron microscopy and X-ray diffractometer. The results show that Fe and Si have formed intermetallic compounds Fe3Si, FeSi, and Fe5Si3.

【 授权许可】

Unknown