Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (06): 1539-1544.doi: 10.3866/PKU.WHXB201204101

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Synthesis and Gas Sensitivity of In2O3/CdO Composite

CHEN Peng-Peng1, WANG Jing1, YAO Peng-Jun1,2, DU Hai-Ying1,3, LI Xiao-Gan1   

  1. 1. School of Electronic Science and Technology, Dalian University of Technology, Dalian 116023, Liaoning Province, P. R. China;
    2. School of Educational Technology, Shenyang Normal University, Shenyang 110000, P. R. China;
    3. Department of Electromechanical Engineering & Information, Dalian Nationalities University, Dalian 116600, Liaoning Province, P. R. China
  • Received:2012-02-01 Revised:2012-04-09 Published:2012-05-17
  • Contact: Wang Jing
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (61176068, 61131004, 61001054).

Abstract: Indium oxide (In2O3) was synthesized using a hydrothermal process. The crystallography and microstructure of the synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The In2O3 had a flower-like hierarchical nanostructure and was composed of tiny near-spherical crystals with a diameter of approximately 20 nm. When In2O3 was mixed with CdO in a 1:1 molar ratio, it was found that the resulting In2O3/CdO composite showed an interesting grape-like porous microstructure following calcinations at elevated temperatures. A gas sensor using this In2O3/CdO composite as the sensing material showed higher sensitivity to different concentration of formaldehyde than the gas sensor based on pure flower-like In2O3 nanomaterials. The In2O3/CdO-based sensors showed a high sensitivity to a concentration of 0.05×10-6 formaldehyde at the optimized operating temperature of 410 °C and a good level of selectivity over other possible interference gases such as ethanol, toluene, acetone, methanol, and ammonia. The gas sensing mechanism of In2O3/CdO sensor has been discussed in detail.

Key words: Composite material, Gas sensor, Formaldehyde vapor, Nano-materials, Porous microstructure