In situ surface Raman study of the induced codeposition mechanism of Ni-Mo alloys

摘要

The induced codeposition of molybdenum with nickel on a Ni-Cu alloy electrode has been investigated by means of in situ surface Raman spectroscopy to obtain information about the codeposition mechanism during electrodeposition of Ni-Mo alloys. The experimental results show that, in the NiSO_4-free solution, molybdate can only be reduced to a mixture of polyvalent molybdenum oxides and/or hydroxide, while, in the case where NiSO_4 coexisted in the solution, molybdate is first reduced to Mo(IV) oxide, which as an intermediate, subsequently is reduced to molybdenum in alloy under the catalysis of inducing nickel.