Chemiresistive sensors based on core-shell ZnO@TiO2 nanorods designed by atomic layer deposition for n-butanol detection
Chemiresistive sensors based on core-shell ZnO@TiO2 nanorods designed by atomic layer deposition for n-butanol detection
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DOI：
10.1016/j.snb.2020.127846
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发表时间：
2020-05
影响因子：
8.4
通讯作者：
Yongshan Xu;Lingli Zheng;Chen Yang;Wei Zheng;Xianghong Liu;Jun Zhang
中科院分区：
文献类型：
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作者：
Yongshan Xu;Lingli Zheng;Chen Yang;Wei Zheng;Xianghong Liu;Jun Zhang
在异质界面处构建具有有效调制电子转移的异质结构为电子器件提供了巨大的机会。在此基础上，成功实现了基于核-壳结构ZnO@TiO2纳米棒的正丁醇高效传感器。TiO 2和ZnO之间形成的n-n异质界面由于它们不同的功函数引起的电子约束而允许电导率的巨大变化，并增强了对暴露于气体分子的响应。研究表明，TiO 2壳层厚度对传感器性能有很大影响，基于6.4 nm厚TiO 2壳层的ZnO@TiO2纳米棒的传感器具有灵敏度高、检测限低（133 ppb）、响应恢复快和对正丁醇检测具有良好选择性等优异的气敏性能.其气敏性能提高的机理主要是由于TiO 2壳层和TiO 2壳层之间形成的异质结结构、TiO 2壳层对氧的吸附增强以及TiO 2壳层的电子耗尽层厚度与德拜长度相当。本文提出的策略具有普遍适用性，可以为设计具有优化性能的高效电子传感器提供一些启示。
Constructing heterostructures with efficient modulation of electron transfer at the heterointerface affords great opportunity for electronic devices. Herein, a high performance nanosensor based on core-shell ZnO@TiO2nanorods is successfully realized for n-butanol detection. The n-n heterointerface formed between TiO2and ZnO allows for vast variation of conductivity due to electron confinement induced by their different works functions and enhances the response on exposure to gaseous molecules. Studies reveals that the shell thickness of TiO2has a great impact on the sensor performances, and the sensor based on ZnO@TiO2nanorods with 6.4 nm-thick TiO2shell delivers outstanding gas sensing properties in terms of high sensitivity, low detection limit (133 ppb), fast response-recovery, and excellent selectivity towards n-butanol detection. The mechanism for the improved gas sensing function is ascribed to the heterojunctions of core-shell nanostructure, the enhanced oxygen adsorption due to the TiO2shell and the fully electron-depleted TiO2shell layer with a thickness comparable to the Debye length. The strategy presented here is generally applicable and can provide some hints to design efficient electronic sensors with optimized performances.