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

Abstract

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.