Microstructure and gas sensing properties of the ZnO thick film treated by hydrothermal method

Pure and Palladium‐Loaded Co3O4 Hollow Hierarchical Nanostructures with Giant and Ultraselective Chemiresistivity to Xylene and Toluene

“…T he Co-HHN andP d-Co-HHN sensors showed sensitivea nd selective detectiono f methylbenzenes with negligible interference from other gases, whereas neither selectivity towards as pecific gas nor ah igh gas response was attained with the Co-CS and Co-HS sensors. Note that the response and selectivity of even the undoped Co-HHN sensor to xylene and toluene at 250 and 300 8Ci nt his study are the highest to have been reported in the literature for pure andc atalyst-loaded oxide semiconductor sensors using SnO 2 , [9,[24][25][26][27] ZnO, [28,29] Fe 2 O 3 , [30,31] WO 3 , [32] TiO 2 , [11] Co 3 O 4 , [12,[33][34][35] Pd-SnO 2 , [10] ZnSnO 3 , [36] Ag-ZnO-SnO 2 , [37] NiO-SnO 2 , [38] TiO 2 -ZnO, [39] Co-ZnO, [40] Cr-NiO, [14] Cr-Co 3 O 4 , [41] Sn-ZnO, [42] Mo-ZnO, [43] TiO 2 -Fe 2 O 3 , [44] Pd-WO 3 , [45] SnO 2 /Fe 2 O 3 , [46] Sb-ZnO, [47] andI n-ZnO [48] (Figure 4e organic sacrificial templates by electrostatic cross-linking between amphiphilic l-(+ +)-lysine molecules in the initial stage of the reaction, followed by the nucleation and growth of cobalt precursors without preferred orientation at the surfaces of the sacrificial templates in the later stages of the reaction. The addition of 5vol %w ater to the stock solution dramatically changed the morphology of Co 3 O 4 from hollow structures with smooth surfaces to hollow hierarchical nanostructures assembled from crystalline nanosheets.…”

Hierarchical hollow ZnO cubes constructed using self-sacrificial ZIF-8 frameworks and their enhanced benzene gas-sensing properties

“…4, the optimum operating temperature ranges from 400 to 450 1C for both ZnO-H and ZnO-S sensors. In addition, the performance of such hierarchical ZnO hollow cubes is superior to mostly other types of ZnO towards gaseous benzene reported previously, [33][34][35][36] as listed in Table 3. The chemical activation of hierarchical hollow ZnO cubes is small for the lower operating temperature, resulting in a poorer gaseous benzene response.…”

Ag-decorated ultra-thin porous single-crystalline ZnO nanosheets prepared by sunlight induced solvent reduction and their highly sensitive detection of ethanol

“…ZnO nanostructure based sensors were reported to show responses to many gases, including ethanol, benzene, toluene, etc. [49]. However, the response comparisons among 100 ppb of ethanol and 10 ppm of other VOCs suggest that the Ag-decorated UTPSC ZnO nanosheet sensor has high selectivity to ethanol as shown in Fig.…”