Author details

It was investigated that a large surface energy and greater amount of O2 vacancies' concentration exist in the NA and NHS surface that increased the ethanol

The conductivity of Ti-ZnO sensor was greater than that of the pure ZnO NRs by a factor of 80.7 that is 1.86%. The ethanol gas sensing response of the ZnO:Ti NR sensor has a linear relationship with temperature. The responses were found at 27.5, 66.7, 117.1, 183.5, 276.5, and 389.5% with 10, 50, 100, 250, 500, and 1000 ppm ethanol concentration, respectively. It was investigated that the responses of ZnO:Ti NR sensor are greater than those of the ZnO NRs at 1000 ppm ethanol concentra-

It was demonstrated that they exhibited good performance for detecting ethanol

It is confirmed from the experimental results that there is no noticeable degradation of the sensor response after the flow of 50 ppm ethanol for consecutive

The response to 10 ppm NO2 became negligibly small (2.3) compared to that at 200 and 300°C (66.3 and 12.4). This shows that with enhancing temperature at 400°C the capability of C2H5OH sensing increases. The selective detection was investigated with ZnO NWs by 200 ppm C2H5OH as compared to that with

The research results show that from a temperature of 300°C the gas response increases abruptly till it attains the maximum value of 400°C. Then, the response decreases rapidly to a temperature limit of 400–430°C. The smaller value of working temperatures (300–400°C), 400°C, was investigated as the OOT for the ZnO NR sensor with 200 ppm ethanol response was observed to have a value of 193.7 [38]. The addition of detection layers in ZnO shows greater value of sensitivity with greater stability/reproducibility to ethanol, and comparatively small response and recovery time relative to the pure layer of MoO3. Ethanol sensing increased with the impurity (Gethanol/Gair). The 25% ZnO in the presence of MoO3 layer as impurity for 500 ppm ethanol attains a level of 171 under nonhumid air. Its response under humid air is 117 (75% r.H. at 21°C). This response is 6 times greater than that for the

The sample has approximate response and recovery time of 3 and 4 min, respectively. As regard the detection characteristics of other ZnO nanoarchitectures working at greater temperatures, the ZnO NR sensors have high response and

detection characteristics at small temperature [53].

tion by about 5.1 [61].

Gas Sensors

pure MoO3 layer [62].

74

vapor even at 380 and 250°C [48].

60 days at the operating temperature [63].

ZnO-SnO2 core shell NWs only at a limit of 1/7 [64].

recovery time when operated at room temperature [47].

Musarrat Jabeen<sup>1</sup> \*, R. Vasant Kumar<sup>2</sup> and Nisar Ali<sup>3</sup>

1 Department of Physics, Government Degree College for Women, Haveli Lakha, Pakistan

2 Department of Material Science and Metallurgy, University of Cambridge, UK

3 Department of Physics Government Post Graduate, Jahanzeb College, Saidu Sharif Swat, Pakistan

\*Address all correspondence to: musarrat97@yahoo.com; musarrat.physics@gmail.com

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