Humidity sensing properties of CeO2–NiO nanocomposite materials

Abstract

CeO 2 -NiO composites were prepared by a simple grind method followed by a heat-treatment process and characterized by X-ray diffraction, transmission electron microscope and nitrogen adsorption-desorption test. Humidity sensing properties of CeO 2 -NiO composites with different mass ratios were studied. The optimal result was obtained for the sample with CeO 2 -NiO mass ratio of 0.5. The impedance of the sensor changes more than five orders of magnitude within the humidity range from 11 to 95 % relative humidity (RH) at 100 Hz. The response and recovery time are about 3 and 19 s respectively, and the maximum hysteresis is \2 % RH. The results indicate the potential applications of CeO 2 -NiO composite (CeO 2 -NiO mass ratio of 0.5) for fabricating high performance humidity sensors.

Electronic to protonic conduction switching in Cu2O nanostructured porous films: the effect of humidity exposure

“…For example, Singla et al 27 reported changes in linear response at 40-60% RH for a polyaniline/Mn 3 O 4 composite doped with organic/inorganic acid. Similarly, Biswas et al 21 reported changes at 55-77% RH for ZnO nanotip arrays, Li et al 26 reported changes at 33-54% RH for a Ce 2 O-NiO composite, and Chung et al 50 reported changes at 45% RH for anodic aluminum oxide. Aer the abrupt change, the response continued to increase in the same direction, up to the present results at 50-60% RH.…”

“…This abrupt change in linear response with increasing RH has been reported for various materials. 21,26,27,50 The RH range within which the response changes varies from material to material, and surface properties such as surface roughness and porosity promote proton hopping. For example, Singla et al 27 reported changes in linear response at 40-60% RH for a polyaniline/Mn 3 O 4 composite doped with organic/inorganic acid.…”

“…Most of the studies available reported on composite semiconducting oxides. [25][26][27][28][29] For example, Hsueh et al 25 reported the fabrication of a humidity sensor by growing CuO nanowires (NWs) on the surface of a glass substrate. The results showed that the sensitivity of the sensor increased with increasing RH level, which was due to the p-type nature of the CuO NWs.…”

“…The results showed that the sensitivity of the sensor increased with increasing RH level, which was due to the p-type nature of the CuO NWs. Li et al 26 reported the humidity-sensing properties of CeO 2 -NiO nanocomposite materials. Singla et al 27 studied the humidity-sensing behavior of a polyaniline/Mn 3 O 4 composite doped with organic and inorganic acids.…”

Humidity sensor based on electrospun (Na0.5Bi0.5)0.94TiO3–Ba0.06TiO3 nanofibers

“…In recent years, more and more researchers are paying their attention to exploitation of materials for humidity sensor with excellent humidity sensing properties including high sensitivity, linear response, and fast response speed [6][7][8][9]. One-dimensional (1D) nanostructures, such as nanofibers, nanowires, and nanotubes, have been gained considerable attention in humidity sensing because of their special physical and chemical properties [10][11][12][13][14].…”