The preparation of NiCo2O4 films by electrostatic spray deposition

The spinel NiCo2O4 has, for many years, been used as an electrocatalyst in electrochemical systems. It also possesses high electrical conductivity and low thermal stability for a compound of this structure. Consequently many deposition techniques used during the fabrication of electrodes may prove to be problematic in, terms of either the deposition itself of the control over the electrode morphology and uniformity. The method of electrostatic spray deposition (ESD) is detailed for the deposition of spinel NiCo2O4, this being shown by X-ray powder diffraction. The films deposited were reproducible in morphology and uniformity and found, through analysis by scanning electron microscopy, to be of high porosity. The electrical resistance was also measured and was found to be low. ESD is therefore shown to be an effective fabrication technique for NiCo2O4 electrodes offering close control over both the catalyst loading and the morphology of the deposition. (C) 2001 Elsevier Science B.V. All rights reserved.