Preparation and Bifunctional Gas Sensing Properties of Porous In2O3-CeO2 Binary Oxide Nanotubes
Preparation and Bifunctional Gas Sensing Properties of Porous In2O3-CeO2 Binary Oxide Nanotubes
复制标题
多孔In2O3-CeO2二元氧化物纳米管的制备及其双功能气敏性能
DOI：
10.1021/ic101602a
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发表时间：
2010-11-15
影响因子：
4.6
通讯作者：
Bai, Xue
中科院分区：
文献类型：
--
作者：
Xu, Lin;Song, Hongwei;Bai, Xue
采用静电纺丝(ESP)法制备了立方相多孔二元In_2O_3-CeO_2氧化物纳米管(NTS)，并用扫描电子显微镜、透射电子显微镜、X射线衍射仪、X射线光电子能谱和紫外可见吸收光谱等手段对其进行了表征。通过调节In_2O_3和CeO_2的摩尔比，最终得到的复合材料的外径和壁厚分别在90-180 nm和15-9 nm范围内可调。随着CeO2含量的增加，二元氧化物的带隙逐渐减小，Ce3+/Ce4+的比值增大，表明表面氧空位逐渐增加。气敏测试表明，当CeO2含量合适时，制备的In2O3-CeO2纳米管可以作为低温(25-110℃)下检测H_2S和较高温度(300℃)下检测丙酮的双功能气敏元件。In75Ce25 NTS传感器是最优的传感器，在80℃时对H_2S的响应最高，为498，在300℃时，对丙酮的响应最高，为30。与纯In_2O_3传感器相比，In75Ce25的响应时间、恢复时间和传感反应势垒高度都显著降低。上述气敏特性可归结为低温硫化和高温吸附两种不同的气敏机理。
The porous binary In2O3-CeO2 oxides nanotubes (NTs) in cubic phase were first fabricated by electrospinning (ESP) method and characterized by SEM, TEM, XRD, XPS and UV-vis absorption techniques. By adjusting the In2O3 and CeO2 molar ratio, the out diameters and wall thicknesses of the final composites were tuned ranging of 90-180 nm and 15-9 nm, respectively. The band gap of the binary oxides gradually decreases, and the ratio of Ce3+ to Ce4+ increases with the increase of CeO2, implying that surface oxygen vacancies gradually increase. The gas sensing test reveals that when the content of CeO2 is appropriate, the as fabricated In2O3-CeO2 NTs could be bifunctional gas sensors to detect H2S at low temperature(25-110 degrees C) while acetone at relative high temperature (300 degrees C). The In75Ce25 NTs sensor is an optimum one, which exhibits the highest response of 498 to H2S at 80 degrees C and the highest response of 30 to acetone at 300 degrees C. In contrast to the pure In2O3 sensor, the response and recovery times, as well as the sensing reaction barrier height, for In75Ce25 both degrade considerably. The above temperature-dependent sensing properties were attributed to two different gas sensing mechanisms, sulfuration at low temperature and adsorption at high temperature.