Hydrothermal synthesis of Ce-doped hierarchical flower-like In_2O_3 microspheres and their excellent gas-sensing properties

摘要

Pure and 1-5 mol% Ce-doped hierarchical flower-like In_2O_3 microspheres with uniform sizes were synthesized via environment friendly one-step hydrothermal method. Their phase structures, morphologies properties and element composition were investigated by different kinds of techniques, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectric spectroscopy (XPS). Their gas-sensing properties were tests for several kinds of Volatile Organic Compounds (VOCs). The results indicated that Ce doping could greatly improve sensing performances of In_2O_3 gas sensors. Among all the samples (0,1,3 and 5 mol% Ce-doped In_2O_3), 3 mol% Ce-doped In_2O_3 exhibited the highest response toward 200ppm acetone at 250℃, having a response of 41.8, which was about 4 times higher than pure In_2O_3. Furthermore, good repeatability and long term stability were achieved, showing its prospect for excellent acetone gas sensor with high performance.