Abstract:

The Fe-Mo alloy induced-codeposition has been studied by in situ surface Raman spectroscopy. In the solution containing 0.2mol•L-1 Na2MoO4．pH＝4．0．the Raman spectra showed three peaks at 940,880 and 450cm-1 corresponding to polymolybdated species on the surface at open circuit potential and -0.3V(vs SCE) at the potential-0.5V, new peaks at about 730, 560, 510, 470 cm-1 appeared in the spectra while a blue film was observed on the surface which can be attributed to mixed-oxidation molybdenum oxides formation. The peak at 730cm-1did not disappear even the potential moved to -1.9V, indication the film annot be further reduced. But in the solution of Na2MoO4 containing 0.1 mol•L-1 FeSO4 and 0.2mol•L-1 citric acid, the peak of mixed-oxidation oxides shifted to 740cm-1 and this peak could fade away gradually in potential region from -1.3 to -1.9V while a silver-white deposit emerged on the surface The results showed that the structure of mixed-oxidation Mo oxides film codeposited with Fe2+ was different from that of the film deposited without Fe2+. The former can be further reduced to form Fe-Mo alloy．

Key words: In situ surface Raman spectroscopy, Fe-Mo alloy, Induced-codeposition