Novel Synthesis Method and Characterization of Nano-Complex Oxide (MFe2O4, M=Co, Mn, Ni, Zn) for Thermochemical Water-Splitting

It was demonstrated that various ferrite materials are very suitable for thermochemical water splitting. In this research, pure crystalline doped ferrites were obtained by means of added sucrose (25 wt%) to the mixture of metal acetates and /or metal citrates dissolved in de-ionized water. The mixture was heated in a microwave oven for 5 minutes which resulted in the formation of an amorphous product. DSC/TGA analysis revealed that the amorphous product crystallizes to form a stable structure at 400^oC. The bulk sample of the amorphous product was heated in muffle furnace to 450 ^oC at a rate of 20^oC/min in air to form a pure ferrite. Average crystallite sizes of the synthesized doped ferrites as calculated from the X-ray diffraction (XRD) peaks were in the range of 15-26 nm. Scanning Electron Microscope (SEM) images of doped ferrites revealed that these nano-crystals were in the form of agglomerates. The BET specific surface areas of the synthesized ferrites were in the range of 43 to 70 m²/g depending on the type of doped metal. Details of the synthesis method and characterization of the synthesized complex oxides with different doped metals will be presented.