Abstract
The surface properties of acetylene black (AB) treated with elemental fluorine or nitric acid have been investigated. An interesting electrochemical behavior of the electrodes with the surface modified ABs has also been discussed from polarization and continuous discharge measurements of oxygen reduction in an alkaline aqueous solution. The results obtained are summarized as follows: By nitric acid treatment, AB surface changed from hydrophobic to hydrophilic and high ability for hydrogen peroxide decomposition because of the increase of surface funtional groups containing oxygen. It was found that the AB treated with fluorine had larger surface area and wettability than those of non-treated one. Oxygen electrodes using the surface-modified AB showed good polarization behavior, because of favorable wettability which was effective to hold stable three phase zone. The stability and the life of electrode were examined in a continuous discharge experiment. As a result, the electrode fabricated from AB treated with fluorine was the most stable and had a long life. That from AB treated nitric acid also exhibited good discharge performance though it was low in its mechanical strength.
