The influence of grinding conditions on the mechanochemical synthesis of zinc stannate

The aim of this work is the investigation of experimental conditions for mechanochemical synthesis of spinel zinc stannate (Zn2SnO4). Application of this material include manufacturing of CO, H-2, NO, NO2, i-C4H10 and C2H5OH gas sensors, production of transparent conducting electrodes, window coatings and anode for use in photoelectrochemistry. Starting powder mixtures of zinc oxide and tin oxide in the molar ratio, in accordance with the stoichiometrics of spinel zinc stannate, were mechanically activated by grinding in a planetary mill for various periods of time in the interval of 0 to 160 min. Changes of physico-chemical characteristics and microstructural parameters in the ZnO-SnO2 system after grinding were followed using surface area analysis and X-ray powder diffraction, while thermal behavior was examined by differential thermal analysis and sensitive dilatometer. The beginning of zinc stannate phase formation was noticed after 40 min of grinding, and prolonged grinding leads to the formation of spinel zinc stannate as the major phase with insignificant amount of unreacted zinc oxide and tin oxide. The formation of spinel was accelerated with the increase of sintering temperature, and monophased zinc stannate was obtained when powder mixture was grinded for 160 min followed by sintering at 1200degreesC. (C) 2004 Kluwer Academic Publishers.