Micromachined twin gas sensor for CO and O2 quantification based on catalytically modified nano-SnO2

From nanowires to cubes of CdO: Ethanol gas response

“…At low temperatures O − 2 is commonly chemisorbed. At high temperatures however O − and O 2− are commonly chemisorbed, while O − 2 disappear rapidly [19]. The reaction kinematics can be described as fallows [20].…”

CHARACTERISTICS OF GAS SENSORS BASED ON ZnO OF DIFFERENT DIMENSIONS

“…Most semiconducting oxide gas sensors are based on the conductivity changes caused by the adsorption and desorption of the gas molecules on the surface of the sensing structure [6]. In ambient air, oxygen molecules can be adsorbed onto the surface of a ZnO sample with n-type conductivity and form O 2 -, O -, and O 2-ions by capturing electrons from the conduction band; the deletion region is formed on the surface of ZnO, resulting in a decrease in carrier concentration and electron mobility [7].…”

Hydrothermal self-assembly of novel porous flower-like SnO 2 architecture and its application in ethanol sensor

“…The detail lattice parameters a, c and crystallite size D of samples are calculated by the XRD data and the Scherrer formula: D = 0.89 /(ˇ cos Â), where is the X-ray wavelength, ˇ is the peak width at half-maximum of the diffraction lines, Â is the Bragg diffraction angle and D is the diameter of the nanostructure, and the results are shown in Table 1. Both the shift of diffraction peaks and the decrease of crystallite size indicate that optimally hydrothermal time can cause lattice distortion of SnO 2 nanoflowers and suppress the growth of SnO 2 crystallites [22,23]. Fig.…”