Nanometer ZnO gas sensing material with different particle size were made by chemical precipitation, emulsion and microemulsion, respectively. Crystal structure and ceramic microstructure of powders were determined by XRD and TEM. The mean grain size and lattice distortion of the materials were calculated with the Cauchy-Cauchy and Debye-Scherrer methods, respectively. Gas sensitivity of ZnO to H-2, SF6, C4H10, gasoline, C2H5OH was measured. It Fan be shown from experimental results that grain size of ZnO gas-sensitive materials can be controlled by means of different processes or surfactants. The gas sensitivity of ZnO gas sensor depends upon its grain size. (C) 2000 Elsevier Science S.A. All rights reserved.
