1959 Volume 23 Issue 1 Pages 71-74
Cathodic potential measurements on Pt, Cu, Ti, Zn, and Al electrodes were carried out at various current densities in aqueous solution of (NH4)2TiF6. The solution contains the cations Ti4+, NH4+ and H+, and the anions TiF6−−, F− and OH− according to the following equations:
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Though Ti4+ ions begin to be reduced at about −0.8 V (vs. S.C.E.), the potential where the titanium deposition becomes visible is less noble than −1.1∼−1.2 V. The mechanism of the electrodeposition of titanium is either the direct discharge of Ti4+ ions or the reduction of titanium ions of lower valency such as Ti3+ or Ti2+ to metallic titanium by active hydrogen, but since a simultaneous evolution of hydrogen with the deposition of titanium was observed, the mechanism could not be identified in the present experiments.