MOF-5衍生In-ZnO纳米颗粒的丙酮气敏性能研究

Study on acetone gas sensitive characteristics of MOF-5 derived In-ZnO nano particles

将溶剂热法制备的MOF-5粉体按照In/Zn摩尔比为0,0.05,0.10,0.15,0.20,0.25和0.30置于硝酸铟水溶液中,经干燥煅烧得到一系列In-ZnO纳米颗粒。X射线衍射仪(XRD)显示In-ZnO保持了ZnO的六角晶体结构,较大的In^(3+)离子替换Zn^(2+)导致了ZnO晶格的膨胀和应力的增加。SEM表明:In-ZnO纳米颗粒保持了纯ZnO的球形和立方介孔结构。气敏性能测试表明:In掺杂降低了ZnO元件的电阻值,提高了其对丙酮的气体响应,并降低了其最佳工作温度,其中In/Zn摩尔比为0.05的In-ZnO纳米颗粒由于较强的多孔性对应较大的比表面积,有利于氧和待测气体分子的吸附,表现出最佳的气敏性能,在200℃的最佳工作温度下对100×10^(-6)丙酮的气体响应值为18.19,响应/恢复时间为2 s/8 s,同时具有很好的选择性和稳定性。

MOF-5 powder is prepared by a solvo thermal method.According to the molar ratio of In/Zn as 0,0.05,0.10,0.15,0.20,0.25 and 0.30,MOF-5 is immersed in indium nitrate aqueous solution containing the required amount of indium,and a series of In-doped ZnO nano particles are obtained after drying and calcination.XRD shows that the In-doped ZnO remains hexagonal crystalline structure of ZnO,and the substitution of In^(3+)larger ions for Zn^(2+)ions leads to the expansion of lattice and increase of stress.SEM indicates that the In-doped ZnO nanoparticles preserve the spherical and cubic mesoporous structure of the pristine ZnO.Gas senstive property measurement shows that the In-doping reduce the resistance of ZnO component,enhance the gas response towards acetone,and lower the prime working temperature.At the prime working temperature of 200℃,the In-doped ZnO nanoparticles with In/Zn=0.05 exhibits the best acetone sensing performance,with the gas response value of 18.19 to 100×10^(-6)acetone,the response/recovery time of 2 s/8 s,as well as good stability and selectivity.