Al_2O_3掺杂ZnO微米花对丙酮超高灵敏度和优异选择性

利用水热合成技术,成功制备具有孔道的纯ZnO微米花和Al_2O_3掺杂的ZnO(Al_2O_3-ZnO)微米花。通过X射线衍射(XRD)、扫描电镜(SEM)、电子能谱(EDS)对样品的形貌和结构进行表征。利用所得的纯ZnO和Al_2O_3-ZnO样品制备气敏元件,并对其气敏特性进行研究。结果表明:在工作温度为260℃时,基于Al_2O_3-ZnO的气敏元件对100×10~(-6)的丙酮气体的灵敏度约为82.8,约为同条件下基于纯ZnO的气敏元件对丙酮气体灵敏度(18.0)的4.6倍,其响应时间和恢复时间分别为3s和8s,是同条件下干扰气体中灵敏度最高的乙醇气体的灵敏度(26.2)的3.16倍,该元件具有优异的选择性,能成功区分具有相似性质的丙酮和乙醇。此外,Al_2O_3-ZnO器件可检测到0.25×10-6的丙酮气体,其灵敏度约为3.1。

Ultrahigh Sensitivity and Excellent Selectivity of Al2O3-doped ZnO Micro-flowers to Acetone

Pore spaced pure ZnO and Al2O3-doped ZnO(Al2O3-ZnO) micro-flowers were successfully synthesized by hydrothermal method .The microstructure ,morphology and components were charac-terized by X-ray diffraction (XRD) ,scanning electron microscopy (SEM ) and energy-dispersive X-ray spectrometry (EDS) ,respectively .Gas sensors were made to investigate the gas sensing properties . The results reveal that the sensor based on Al2O3-ZnO shows a high sensitivity to acetone .The sensi-tivity is 82 .8 to 100 × 10-6 acetone gas at 260℃ ,which is about 4 .6 times larger than that of pure ZnO (18 .0) at similar conditions .The response time and recovery time are about 3s and 8s ,respectively . Al2O3-ZnO also show s an excellent selectivity .Its sensitivity to acetone is 3 .16 times higher than that to ethanol , which has the highest sensitivity among interfering gases under the same conditions . Thus ,Al2O3-ZnO sensors can successfully distinguish acetone and ethanol with similar properties .In addition ,the lowest detection to acetone is about 0 .25 × 10-6 with theresponse is about 3 .1 .