| 摘要 |
A titanium dioxide rectifier is prepared by partially oxidizing the surface of a titanium plate, by heating in an atmosphere containing oxygen, further oxidizing the surface by electrolytic anodization and then applying a counter electrode metal of high work function such as bismuth, nickel or platinum. The surface of the titanium plate is first cleaned by abrasive or acid treatment, e.g. by immersion in a mixture of 80 per cent nitric and 20 per cent hydrofluoric acids, and then heated in air or steam at between 600 DEG C. and 800 DEG C., if in air, a further heat treatment in a reducing atmosphere such as hydrogen being given. The counter electrode may be applied by application of the molten metal or by vapour deposition. Specification 733,267, [Group XXXVI], is referred to. |
