Generation of oxygen vacancies in ZnO nanorods/films and their effects on gas sensing properties

Correlation between optical characteristics and NO2 gas sensing performance of ZnO nanorods under UV assistance

“…Evidently, all the samples have the two emission bands with a weak band of 381 nm (assigned to near band gap emission of the ZnO nanorods) and broad visible band of 400-750 nm. The visible emission band is assigned to the deep defects in ZnO nanorods [1,[19][20][21]. Fig.…”

“…Liao, et al have investigated that oxygen vacancies in ZnO nanorods dominated the electronic properties and adsorption behaviors, because they acted as donors to provide electrons to the ZnO conduction band [19]. Further, it was found that the defects (oxygen vacancies (V O ); oxygen interstitial (O i ); oxygen antisite (O Zn ); zinc vacancies (V Zn ); zinc interstitial (Zn i )) influenced the sensing performance of ZnO-based gas sensors [1,19,20]. In general, ZnO nanooxides' defects can be modified through annealing processes.…”

A high performance methanol gas sensor based on palladium-platinum-In2O3 composited nanocrystalline SnO2

“…Among different sensor types, metal oxide semiconductor (MOSs) gas sensors are the most popular type as it is more practical and market-oriented. A series of promising metal oxide, such as SnO 2 , In 2 O 3 , ZnO, TiO 2 , Fe 2 O 3 [6][7][8][9][10], and so on, has been used as sensing materials of gas sensors. They can test the toxic gases of ambient atmosphere through changes in the resistance of metal oxide.…”

Fabrication of ZnO/CdS, ZnO/CdO core/shell nanorod arrays and investigation of their ethanol gas sensing properties

“…Among these 1D nanostructured metal oxides, ZnO is one of the most widely studied materials for gas sensors because it demonstrates thermal and chemical stability under standard operating environments, high conductivity and non-toxicity [1][2][3][4][5][6][7][8]. Recently, various types of approaches have been implemented to enhance the gas sensing properties of ZnO-based gas sensors: changing nanostructures [9][10][11][12][13], modifying surface defects [14,15], and employing other materials on the surface to create heterostructures [16][17][18][19]. In particular, heterostructures involving the incorporation of noble metals onto ZnO surfaces is widely employed to improve the reactions between adsorbed surface oxygen species on ZnO and reducing gases [20][21][22][23].…”

“…By comparing the analytic results and gas sensing properties, we investigated the mechanism of core/shell nanorod formation and the effects of CdS and CdO on the gas sensing properties of ZnO nanorods. The ethanol gas sensing properties of the ZnO-based gas sensors were tested in a furnacetype sensing system that we described in a previous study [14,16], and the sample was aged in the tube at 500°C for 2 days before performing any gas sensing tests. …”