Samples of Ni and Co mixed oxide in the form of powders were synthesised by thermal decomposition of the nitrates at 400 degrees C. The samples were characterized by XRD for the crystal structure, XPS for the surface composition, the BET method for the surface area and by potentiometric titration to measure the point of zero charge (pzc). Lattice parameters and average crystallite size have been obtained from the X-ray analysis, the surface composition shows strong enrichment with Ni, while the pzc increases from 0 to about 40% Ni to remain constant up to purr NiO, Inner layer capacitance and electrochemical (wet) surface area have also been derived from potentiometric titration curves. The results have been discussed in comparison with other few data in the literature.