| Autor: |
Abdul Haroon Rashid SSA, Sabri YM, Kandjani AE, Harrison CJ; School of Engineering , RMIT University , Melbourne 3001 , Victoria , Australia., Canjeevaram Balasubramanyam RK; School of Engineering , RMIT University , Melbourne 3001 , Victoria , Australia.; CNRS, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB) , University of Bordeaux , UMR 5026, 87, Avenue du Docteur Schweitzer , Pessac Cedex F-33608 , France., Della Gaspera E, Field MR, Bhargava SK, Tricoli A; Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australian Capital Territory , Australia., Wlodarski W; School of Engineering , RMIT University , Melbourne 3001 , Victoria , Australia., Ippolito SJ; School of Engineering , RMIT University , Melbourne 3001 , Victoria , Australia. |
| Abstrakt: |
In this report, the gas sensing performance of zinc titanate (ZnTiO 3 ) nanoarrays (NAs) synthesized by coating hydrothermally formed zinc oxide (ZnO) NAs with TiO 2 using low-temperature chemical vapor deposition is presented. By controlling the annealing temperature, diffusion of ZnO into TiO 2 forms a mixed oxide of ZnTiO 3 NAs. The uniformity and the electrical properties of ZnTiO 3 NAs made them ideal for light-activated acetone gas sensing applications for which such materials are not well studied. The acetone sensing performance of the ZnTiO 3 NAs is tested by biasing the sensor with voltages from 0.1 to 9 V dc in an amperometric mode. An increase in the applied bias was found to increase the sensitivity of the device toward acetone under photoinduced and nonphotoinduced (dark) conditions. When illuminated with 365 nm UV light, the sensitivity was observed to increase by 3.4 times toward 12.5 ppm acetone at 350 °C with an applied bias of 9 V, as compared to dark conditions. The sensor was also observed to have significantly reduced the adsorption time, desorption time, and limit of detection (LoD) when excited by the light source. For example, LoD of the sensor in the dark and under UV light at 350 °C with a 9 V bias is found to be 80 and 10 ppb, respectively. The described approach also enabled acetone sensing at an operating temperature down to 45 °C with a repeatability of >99% and a LoD of 90 ppb when operated under light, thus indicating that the ZnTiO 3 NAs are a promising material for low concentration acetone gas sensing applications. |
