Synthesis of ZnTe powders from green solvents by a solvothermal method. Study of the sensing properties in a CO atmosphere

In this work, the characterization and testing of sensing properties of ZnTe powders for detecting carbon monoxide were investigated. The ZnTe synthesis was reached by a solvothermal process, using three different green solvents, methanol, ethanol, and isopropanol. The structural, morphological, and compositional properties of ZnTe powders were analyzed by X-ray diffraction, XRD, scanning electron microscopy, SEM, and atomic force microscopy, AFM, and X-ray energy dispersion (EDS), respectively. XRD confirmed the zincblende-type cubic phase of ZnTe, with crystallite sizes of the order of 69 nm. SEM images of all synthesized samples showed a surface covered with particles of different sizes and irregular morphologies. Finally, the sensing response of ZnTe samples to CO was measured for concentrations varying from 1 to 500 ppm at different operating temperatures, 100, 200, and 300 °C. The highest sensitivity, 18.4, was obtained for ZnTe samples synthesized from isopropanol as solvent, so ZnTe powders showed a good response for CO detection, resulting these materials promising to be applied as gas sensors.