PREPARATION OF CATALYTIC CATHODE FOR ELECTROLYSIS

PURPOSE:To prepare a catalytic electrode with reduced hydrogen overvoltage and long life, by electroplating a conductive substrate in a plating bath containing a cobalt salt, ammonium sulfate, a trivalent or tetravalent titanium compound and alkali fluoride in a specific ratio and having pH adjusted to a specific value. CONSTITUTION:In a plating bath which contains 0.1-1.3mol/l cobalt salt and 0.07-3mol/l ammonium sulfate and of which the ratio of Ti/Co is adjusted to 0.01-0.4 and the ratio of Ti/F to 0.12-0.22 by containing a trivalent or tetravalent titanium compound and alkali fluoride in combination and pH to 2.5-7, a conductive substrate is electroplated. As the cobalt salt, cobalt sulfate is used, as the titanium component, the trivalent titanium compound such as titanium trichloride or the tetravalent titanium compound such as titanium sulfate is used and, As the F component, M2TiF6 is used. The electrolating is carried out at a bath temp. of about 40-80 deg.C and current density of about 0.1-10A/dm and the thickness of a plating layer is adjusted to about 10-50mum.