TY - JOUR
T1 - Research on the electrochemical behavior of Si(IV) on the tungsten electrode in CaCl2–CaF2–CaO molten melt
AU - Jidong Li, Li
AU - Ren, Hao
AU - Guo, Feng
AU - Lu, Jinlin
AU - Li, Jing
AU - Yang, Yongxiang
PY - 2018
Y1 - 2018
N2 - Abstract: At 1023 K, the electrochemical behavior of Si(IV) on the tungsten electrode in CaCl2–CaF2–CaO–SiO2 molten salt was studied by cyclic voltammetry, square-wave voltammetry and open-circuit chronopotentiometry. The reduction potential of Si(IV) started at –0.68 V, and the intermediate product CaC2 was observed at –1.78 V. The reduction of Si(IV) on the tungsten electrode was a one-step four-electron transition, which was a diffusion-controlled mass transfer process. The diffusion coefficient for the reduction process of Si(IV) ions was estimated to be 3.22 × 10–5 cm2 s–1 at 1023 K. With the temperature interval from 993 to 1183 K, the diffusion activation energy was calculated to be 4.425 kJ mol–1. Moreover, the deposition of Si(IV) occurs when the applied potential is less than –0.6 V (vs. Pt wire). The present electrochemical study on Si(IV) in the molten salt will be a theoretical reference for future silicon electrorefining.
AB - Abstract: At 1023 K, the electrochemical behavior of Si(IV) on the tungsten electrode in CaCl2–CaF2–CaO–SiO2 molten salt was studied by cyclic voltammetry, square-wave voltammetry and open-circuit chronopotentiometry. The reduction potential of Si(IV) started at –0.68 V, and the intermediate product CaC2 was observed at –1.78 V. The reduction of Si(IV) on the tungsten electrode was a one-step four-electron transition, which was a diffusion-controlled mass transfer process. The diffusion coefficient for the reduction process of Si(IV) ions was estimated to be 3.22 × 10–5 cm2 s–1 at 1023 K. With the temperature interval from 993 to 1183 K, the diffusion activation energy was calculated to be 4.425 kJ mol–1. Moreover, the deposition of Si(IV) occurs when the applied potential is less than –0.6 V (vs. Pt wire). The present electrochemical study on Si(IV) in the molten salt will be a theoretical reference for future silicon electrorefining.
KW - diffusion coefficient
KW - electrochemical behavior
KW - nucleation mode
KW - silicon
UR - http://www.scopus.com/inward/record.url?scp=85055410527&partnerID=8YFLogxK
U2 - 10.3103/S1067821218050085
DO - 10.3103/S1067821218050085
M3 - Article
AN - SCOPUS:85055410527
SN - 1067-8212
VL - 59
SP - 486
EP - 492
JO - Russian Journal of Non-Ferrous Metals
JF - Russian Journal of Non-Ferrous Metals
IS - 5
ER -