Comparison of the enhanced gas sensing properties of tin dioxide samples doped with different catalytic transition elements.
In this work, non-doped SnO2 samples, and SnO2 samples doped with Zn(II), Cu(II), or Mn(II), having hierarchical microstructures, were prepared using an otherwise identical hydrothermal process, followed by annealing. The morphological and structural characteristics of the samples were systematically characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS). Ten gas sensors were constructed from each material, and compared as to detection of gas-phase ethanol, acetone, glacial acetic acid, methanol, and ammonia. The results indicated, for example, that SnO2 containing 2.91% Mn dopant exhibited a 2.5-fold higher gas detection response toward ethanol at 100 ppm than that of the non-doped material. The fastest response time for 100 ppm ethanol was found for Cu(II)-doped SnO2 (9.7 s), compared with 12.4 s for non-doped SnO2. Graphs of sensor response versus operating temperature for SnO2 containing different types and quantities of dopant exhibited quite different morphologies. The gas-sensing mechanism appears to involve reactions between the detected gases and the various oxygenous ions, such as O, O2(-), and O(2-), present at the surface of the sensor.
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China; Graduate School of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Fuchao
F
Yang
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China; Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education, Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062, People's Republic of China. Electronic address: zguo@licp.cas.cn.
Zhiguang
Z
Guo
Gas sensing properties; Hierarchical SnO(2); Sensing mechanism; Zn (Cu/Mn) doping