Cobalt ferrites are deposited on Al(2)O(3) substrates via atomic layer deposition, and the efficacy of using these in a ferrite water splitting redox cycle to produce H(2) is studied. Experimental results are coupled with thermodynamic modeling, and results indicate that CoFe(2)O(4) deposited on Al(2)O(3) is capable of being reduced at lower temperatures than CoFe(2)O(4) (200-300 degrees C) due to a reaction between the ferrite and substrate to form FeAl(2)O(4). Although the reaction of FeAl(2)O(4) and H(2)O is not as thermodynamically favorable as that of FeO and H(2)O, it is shown to be capable of splitting H(2)O to produce H(2) if non-equilibrium conditions are maintained. Significant quantities of H(2) are produced at reduction temperatures of only 1200 degrees C, whereas, CoFe(2)O(4) produced little or no H(2) until reduction temperatures of 1400 degrees C. CoFe(2)O(4)/Al(2)O(3) was capable of being cycled at 1200 degrees C reduction/1000 degrees C oxidation with no obvious deactivation. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.