NO2 sensing characteristics of ZnO nanorods prepared by hydrothermal method

Abstract

ZnO nanorods were prepared via a hydrothermal reaction in a solution containing Zn(NO 3 ) 2 ·6H 2 O, NaOH, cyclohexylamine, ethanol and water, and their NO 2 and CO sensing behaviors were investigated. The morphology and agglomeration of ZnO nanorods could be manipulated by controlling the amount of water in the solution, which was explained by the variation in the [OH − ] due to an interaction between the water and cyclohexylamine. Sea-urchin-like and well-dispersed ZnO nanorods were prepared at low and high water content, respectively. Well-dispersed ZnO nanorods showed 1.8 fold change in resistance at 1 ppm NO 2 while there was no significant change in resistance at 50 ppm CO. The present ZnO nanorods can be used in automated car ventilation systems to detect NO 2 in the presence of CO.

Fabrication of NOx gas sensors using In2O3–ZnO composite films

“…Among the materials used, In 2 O 3 is known to be sensitive to some oxidizing gases, such as NO x [5][6][7][8]16] and ozone [9,10]. In order to improve the sensor sensitivity, nanostructured In 2 O 3 [11,12] or binary oxide films [13,14] have been used.…”

“…In order to improve the sensor sensitivity, nanostructured In 2 O 3 [11,12] or binary oxide films [13,14] have been used. On the other hand, zinc oxide (ZnO) also has been proposed as a sensing material for the detection of some pollutants [15,16]. Besides, ZnO has been reported as an effective dopant to improve the sensor sensitivity.…”

Improving the H2 Gas Sensitivity of ZnO Thin Films by Modifying the Annealing Conditions

“…Many research groups have investigated and reported on the nanostructure and sensing properties of metal oxide semiconductor gas sensors such as In 2 O 3 , Fe 2 O 3 , SnO 2 , ZnO, WO 3 , and TiO 2 . [1][2][3][4][5][6][7] Among these metal oxides, ZnO in its various forms has been reported to have remarkable ability for detection of hazardous gases such as H 2 , CO, H 2 S, NH 3 , NO 2 , and C 2 H 5 OH. [8][9][10][11][12][13] Fabrication of sensor devices using nanostructured materials has proved to be an important approach for improving the efficiency of these devices.…”

CO gas sensing properties in Pd-added ZnO sensors

“…Oxide semiconductor ZnO has been extensively studied as a gas sensor detecting gases such as CH 4 , CO, H 2 , C 2 H 5 OH, Cl, and H 2 S [1][2][3][4][5][6][7][8][9], based on the resisivity changes from adsorption/desorption and reactions with target gases. Several forms of sensors have been fabricated including single crystal [1], sintered bodies [1,6], thick layers [8], thin films [2,3,5,7], and nano structures [4,9].…”

“…Several forms of sensors have been fabricated including single crystal [1], sintered bodies [1,6], thick layers [8], thin films [2,3,5,7], and nano structures [4,9]. The sensing performance (magnitude of gas response (sensitivity), selectivity, sensing temperature, and so on) depends on the electronic and structural properties of the sensor materials, and a common approach to improve the sensing properties is to employ the metal additives such as Al, Sb, Cu, and Pt [5,8,10,11].…”