ISSN: 1003-6326
CN: 43-1239/TG
CODEN: TNMCEW

Vol. 29    No. 8    August 2019

Mechanism of MoO2 electrodeposition from ammonium molybdate solution
Hua-zhen CAO, Cheng-jian TONG, Hui-bin ZHANG, Guo-qu ZHENG
(College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China)
Abstract: A mechanism study on MoO2 electrodeposition from ammonium molybdate solution was presented via linear sweep voltammetry, species distribution diagram, Raman spectra, Fourier transform infrared spectrometry and X-ray diffractometry. The results show that there exist two reducible species in ammonium molybdate aqueous solution, i.e. and molybdenum ammonium complex. In weak acid medium without , an obvious reduction peak denoting the reduction of to molybdenum(IV) oxides emerges at around -0.7 V (vs SCE). While in neutral and basic solutions without , the dominant species changes to , and accordingly, no reduction peak appears except hydrogen evolution. plays an important role in MoO2 electrodeposition. A new current peak appears at -1.25 V (vs SCE) in both acid and basic solutions, which is attributed to the reduction of molybdenum complex. The effects of solution composition and the electrodeposition conditions on the current efficiency were discussed systematically. By optimizing the electrodeposition conditions, the current efficiency can reach up to 51.9%.
Key words: MoO2; NH4+; sodium molybdate; electrodeposition; current efficiency; mechanism
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
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