Thermal investigations of the Sn–Zn–O gels obtained by sol–gel method

ZnO–SnO₂ nanostructures are of great interest in practical applications such as optoelectronic devices, gas sensors and catalyst supports due to their excellent optoelectronic and highly sensitive gas sensing properties. In the present work, oxide powders of Sn, Sn/Zn = 1:1, Sn/Zn = 1:2 and Zn were synthesized by sol–gel method. Thermal behavior of the obtained gels was determined by thermogravimetry and differential thermal analysis coupled on-line with mass spectrometry (TG/DTA–MS) in air and nitrogen atmosphere. In air, endothermic effects due to the decomposition of the precursors and exothermic effects due to the oxidation of the organic part were observed. In the case of nitrogen atmosphere, only endothermic effects take place. The XRD and FTIR investigations have shown the same structure both for DTA resulted residues in air and for samples isothermally treated at 500 °C for 1 h. Based on the obtained results, the thermal treatment of the samples was established depending on their intended applications. In the experimental conditions used, the formation of ZnSnO₃ was not confirmed.