PREPARATION OF HYDROPHOBIC PLATINUM-ELECT RODES BY COMPOSITE-PLATING

Hydrophobic platinum electrodes were prepared by composite-plating pla tinum with poly (tetrafluoroethylene) (PTFE) fine particles on platinu m substrates in an amidosulfuric acid-dinitrodianmine platinum complex bath containing a cationic surfactant under ultrasonic irradiation. T he electrodes plated under optimized conditions had contact angles wit h water higher than 150 deg., and were stable when polarized anodicall y and cathodically at a current density of 200 mA cm(-2) for 10 h in s trongly acidic, neutral and strongly alkaline solutions. Significant h ydrophobic effects on hydrogen-oxygen overvoltages and current efficie ncy for electroorganic processes were also observed on the electrodes.