ELECTROCHEMICAL-BEHAVIOR OF AN ELECTRODEPOSITED RHODIUM ELECTRODE IN ALKALINE-SOLUTION

The electrochemical properties of an electrodeposited rhodium electrode on a titanium substrate in 1 mol dm-3 NaOH solution have been investigated by potentiodynamic, potentiostatic and ac impedance measurements. The Tafel slopes of 125 mV/decade for the oxygen evolution reaction have been obtained on both electrodeposited and rhodium wire electrodes. The electrodeposited layer of rhodium behaves in a similar way as the rhodium wire electrode. The charge enhancement factor is, however, smaller on the electrodeposited electrode and so is the reversibility of the surface oxidation-reduction process. The stability of the electrodeposited layer under anodic polarization at +0.8 V vs. SCE is good without any significant dissolution of the rhodium layer. © 1990.