毛线团状In_(2)O_(3)空心球的合成及其气敏性能研究

Study on the Synthesis of Yarn Ball-Like In_(2)O_(3) Hollow Sphere and Its Gas Sensitivity

采用模板法成功制备了具有介孔结构的毛线团状In_(2)O_(3)空心球,该空心球具有大的比表面积(30.88 m^(2)/g),并研究了苯二甲酸的种类对产物形貌、结构和气敏性能的影响。利用XRD、TEM、FT-IR、DSC-TG和氮气物理吸附对所合成的产物进行表征。结果表明苯二甲酸的种类对最终产物的形貌有显著影响。气敏性分析表明,与其他In_(2)O_(3)及其体状材料相比,基于毛线团状In_(2)O_(3)空心球的传感器对乙醇表现出优异的气敏性能。用对苯二甲酸所合成的In_(2)O_(3)空心球在工作温度为280℃时对100 ppm乙醇的响应值约为28,是In_(2)O_(3)体状材料的3倍以上。该传感器对10 ppm的乙醇也有着高的气敏响应值(约为3.6),其能够检测到环境中的低浓度乙醇气体。其响应与恢复时间分别为16s和39s,具有快速响应和恢复的特性。此外,该传感器在30 d的稳定性测试后响应值还能达到初始值的91%,表明毛线团状In_(2)O_(3)空心球在检测乙醇气体方面具有优异的气敏稳定性能。

Yarn ball-like In_(2)O_(3) hollow spheres with mesoporous structure are successfully prepared by using the template method,which has a large specific surface area(30.88 m^(2)/g).The effects of the type of benzoic acid on the morphology,structure and gas sensitivity of the final products are studied.The as-synthesized samples are characterized by XRD,TEM,FTIR,DSC-TG and N_(2) physisorption.It is found that the type of benzoic acid has an obvious influence on the morphology of the final products.The gas sensing results show that the sensor based on yarn ball-like In_(2)O_(3) hollow sphere show excellent gas sensing performance to ethanol compared with other In_(2)O_(3) and its bulk.The response value of the In_(2)O_(3) hollow sphere synthesized by using terephthalic acid is about 28 to the 100 ppm ethanol at 280℃,which is more than 3 times of that of the In_(2)O_(3) bulk.The sensor also has a high gas sensitivity response value of 3.6 to 10 ppm ethanol,which can detect low-concentration ethanol gas in the environment.Its response and recovery time are 16 s and 39 s,respectively,showing fast response and recovery characteristics.Moreover,its gas sensitivity response value can reach 91%of the initial value after 30 days of stability test,indicating that the gas sensor has excellent gas sensitivity stability in detecting ethanol gas.