Synthesis and structure study of ZnCo2O4 spinel prepared via coprecipitation process


Abstract in English

ZnCo2O4 spinel was successfully prepared via co-precipitation process starting from corresponding metal chlorides in aqueous solutions at pH=13. Different calcination temperatures (400-500- 600-700-800-1000oC) and different Zn:Co molar ratios (1:2 - 1:2.5) were applied in an effort to prepare this important spinel with perfect specifications starting from cheap, easy to handle inorganic precursors and using a simple process. This process was chosen for its simple requirements and the ability to modify the resulting spinel characteristics by adjusting different parameters easily like mixing temperature, time and speed and the drying conditions. The resulting samples were characterized using x-ray powder diffraction (XRPD), Fourier transform Infra-Red spectroscopy (FT-IR), Differential thermal analysis (DTA). The coloration, crystallinity size, formation and decomposition of the resulting ZnCo2O4 were found to depend on the calcination temperatures, Zn:Co molar ratio and stirring time. Results showed that ZnCo2O4 spinel was formed at relatively low temperatures. All the samples shared a cubic structure with Fd3m space group.

References used

C.N.R. Rao, B. Raveau, 1998- Transition Metal Oxide. Wiley, New York
P.A. Cox, 1992 - Transition Metal Oxides: An Introduction to Their Electron Structure and Properties, Clarendon Press, Oxford
E.P. Wohlfarth, 1982- Ferromagnetic Materials. North-Holland, Amsterdam
a) X.F. Chu, X.Q. Liu, G.Y. Meng, 1999- Preparation and gas sensitivity properties of ZnFe2O4 semiconductors, Sens. Actuators B 55, 19-22; (b) G.L. Castiglioni, G. Minelli, P. Porta, A. Vaccari,2000- Synthesis and properties of spinel-type Co Cu Mg Zn Cr mixed oxides, J. Solid State Chem. 152 ,526–532; (c) X.S. Niu, W.P. Du, W.M. Du,2004- Preparation and gas sensing properties of ZnM2O4 (M = Fe, Co, Cr), Sens. Actuators B 99 ,405–409)
R. Alc´antara, M. Jaraba, P. Lavela, J.L. Tirado,2002- NiCo2O4 spinel: first report on a transition metal oxide for the negative electrode of sodium-ion batteries, Chem. Mater. 14 , 2847–2848

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