Abstract:

CeO₂-In₂O₃ composites were synthesized by pyrolysis metal-organic framework method (MOFs) using In(NO₃)₃∙4.5H₂O and Ce(NO₃)₃∙6H₂O as raw materials, terephthalic acid as ligand and N, N-dimethylformamide as organic solvent. The microstructure of the obtained materials was characterized by XRD, TEM, SEM, UV-vis and BET. The gas sensitive properties of obtained CeO₂-In₂O₃ composites were studied. The results indicated that when the molar ratio of In/Ce was 3∶1, CeO₂-In₂O₃ to 1×10⁵μg/L triethylamine (TEA) had the highest response values (48.37), which was 5 times that of pure In₂O₃ (9.45), response/recovery time was reduced to 36s/22s, and the composite had excellent selectivity and long-term stability at the optimum operating temperature of 173℃. The increased sensing performance can be attributed to the large specific surface area provided by pyrolytic metal-organic skeleton method and the formation of n-n heterojunction.

Key words: CeO₂-In₂O₃, triethylamine, gas sensitive performance, gas sensitive mechanism, heterojunction

摘要：

以In(NO₃)₃∙4.5H₂O和Ce(NO₃)₃∙6H₂O为原料，对苯二甲酸为配体，N,N-二甲基甲酰胺为有机溶剂，通过热解金属有机骨架法（MOFs）成功制备了CeO₂-In₂O₃复合材料。采用X射线双晶粉末衍射仪（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、紫外-可见漫反射吸收光谱（UV-vis）和比表面积与孔隙度分析仪（BET）对材料的微观结构进行表征，研究了CeO₂-In₂O₃复合材料的气敏性能。结果表明，当In/Ce摩尔比为3∶1时，CeO₂-In₂O₃对1×10⁵μg/L三乙胺（TEA）的响应值（48.37）最高，是纯In₂O₃（9.45）的5倍，响应/恢复时间缩短至36s/22s，且该复合材料在173℃的最佳工作温度下具有优异的选择性和长期稳定性。复合材料传感性能的增强可归因于热解金属有机骨架法提供的大比表面积以及n-n异质结的形成。

关键词: CeO₂-In₂O₃, 三乙胺, 气敏性能, 气敏机理, 异质结