•  
  •  
 

Corresponding Author

Jian-xin QIN(qdqinjianxin@163.com)

Abstract

The influences of ferrous/ferric (Fe2+/Fe3+) interconvertion on electrochemical reduction and electrode reaction of Fe3+ were investigated by using linear sweep voltammetry, potentiostatic method and cyclic voltammetry (CV) in acidic electrolytes containing chloride ion (Cl- ) and sulfate ion (SO42-). It was shown that the reduction process of Fe3+/Fe2+ would take place in two independent stages: (1) the reduction of Fe3+ to Fe2+ at E=0.35V and (2) the co-precipitation of Fe2+ by forming Fe(OH)2 (E≤-0.3 V) instead of Fe. The major effect of Fe2+/Fe3+ interconvertion on the reduction is the |ipa/ipc| of quasi-reversible and equilibrium potential in the first stage. Practically speaking, the |ipa/ipc| values increased with the increase of c(Fe3+ )/c(Fe2+ ), and the values of |ipa/ipc| at fast sweep rates were less strongly affected than those at slow sweep rates. The least variation in |ipa/ipc| (|ipa/ipc|≈1.20) with sweep rate was observed in 0.50 mol·L-1 Fe2+ and 0.50 mol·L-1 Fe3+ solutions. Meanwhile, the equilibrium potential was also affected by c(Fe3+ )/c(Fe2+ ). The equilibrium potential shifted more positively from E1=0.501 V in No. ① to E5=0.565 V in No. ⑤ among the five samples studied in this work.

Graphical Abstract

Keywords

Fe2+/Fe3+ interconvertion, cyclic voltammetry, polarization curve, reduction behavior

Publication Date

2017-12-28

Online Available Date

2017-03-30

Revised Date

2017-03-03

Received Date

2016-11-29

References

[1] Shi Y H(史艳华). Effect of Fe2+ concentration on the electrodeposition Fe-Ni coating on 20 steel[J]. Journal of University of Science and Technology Beijing(北京科技大学学报). 2011, 33(3):313-317

[2] Maria Poroch-Seritan, Lgor Cretescu, Corneliu Cojocaru,et al. Experimental design for modelling and multi-response optimization of Fe€“Ni electroplating process[J]. Chemical Engineering Research and Design,2015, 4(96):138-149.

[3] Ju-Hwan Kim, TaiHong Yim, Jae-Ho Lee. Effects of bath and operating conditions on the composition of Ni€“Fe alloy electroplating for solar cell substrate[J]. Current Applied Physics, 2013, 13(2):S108-S110.

[4] Mingming Lan, Huiqin Li, Weihua Huang, et al. Effect of cathode vibration and heat treatment on electromagnetic properties of flake-shaped diatomite coated with Ni€“Fe alloy by electroplating[J]. Journal of Magnetism and Magnetic Materials, 2015, 377:243-251.

[5] MH Seo, JK Dong, JS Kim. The effects of pH and temperature on Ni€“Fe€“P alloy electrodeposition from a sulfamate bath and the material properties of the deposits[J]. Thin Solid Films, 2005, 489(1€“2):122-129.

[6] Tian H(田华).Study on iron electroplating and Fe-SiC composite electroplating technices[D]. Qingdao: Qingdao University of Science and Technology(青岛科技大学),2009.11-17.

[7] Zhou Y M(周雍茂),LIU M(刘铭). Potential-pH diagrams for the Fe-H2O system based on the principle of simultaneous equilibrium [J]. Journal of Changsha university of Science and Technology(Natural Science)长沙理工大学学报(自然科学版), 2004, 1(2):89-92.

[8] Caldcron E H, Wuthrich, Mandin P, et al. Estimation of the effectiveness factor of an outer-sphere redox couple (Fe2+/Fe3+) using rotating disk Ti/IrO2 electrodes of different loading[J]. Journal of applied electrochemistry, 2009, 39(8):1379-1394.

[9] Derek Pletcher, Helen Saxton. A first course in electrode processes[M]. Royal Society of Chemistry, 2009.

[10] Lu S J(鲁思伽),Hong J(洪军),Qi SH L(祁士华), et al. Transform rules between Fe2+/Fe3+ in the UV/Fenton system[J]. Acta Scientiae Circumstantiae(环境科学学报), 2009, 29(6):1258-1262.

[11] Qin S H, Meng J, Tang X H, et al. Monitoring the inorganic chemical reaction by surface-enhanced Raman spectroscopy: A case of Fe3+ to Fe2+ conversion[J]. Talanta, 2016, 146:452-456.

[12] Jean Horkans. On the role of buffers and anions in nichel-iron electrodeposition[J]. J. Electrochem. Soc., 1979,126(11):1861-1867.

[13] Bard A J, Faulkner L R.. Electrochemical Methods-Fundamentals and Applications[M]. New York: John Wiley&Sons,INC, 1980. 237.

[14] Z.-W. Tian(田昭武). Electrochemical Research Methods(电化学研究方法) [M]. Beijin:Science Press (科学出版社),1984,3:4-7.

[15] Allen J. Bard, Larry R. Faulkner. Electrochemical Methods Fundamentals and Applications[M]. New York: John Wiley&Sons,INC, 1980. 51-53.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.