ELECTRODEPOSITION OF COPPER-OXIDE FROM THE EUTECTIC SODIUM-POTASSIUM NITRATE MELT

Copper injected anodically into eutectic Na-K nitrate melt at 300-degr ees-C is shown to deposit cathodically as cupric oxide (CuO). The diss olved copper is in the +2 oxidation state and apparently forms a nitra to complex that facilitates reduction of nitrate to oxide (and nitrite ) at potentials more than a volt positive of that for reduction of the Na/K nitrate species. From these results and literature studies, cath odic metal oxide deposition from nitrate melts appears to be a general phenomenon that could prove to be a practical means of preparing anhy drous metal oxide films.