Centre for Theoretical and Computational Molecular Science, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld 4072, Australia.
Nanotechnology. 2017 Oct 13;28(41):415502. doi: 10.1088/1361-6528/aa8395. Epub 2017 Aug 2.
Thanks to the growing interests of metal oxide sensors in environmental and industrial uses, this study presents the sensing mechanism of methane gas (CH) on recently synthesized two-dimensional form of ZnO, ZnO nano sheets (ZnO-NS). The adsorption energy of CH on pristine ZnO-NS, calculated by means of van der Waals corrected first-principles calculations, is found to be insufficient restricting its application as an efficient nano sensor. However, the creation of (O/Zn) vacancies and the substitution of foreign dopants into ZnO-NS considerably intensify the binding energy of CH. Through a comprehensive energetic analysis, it is observed that among all the substituents, boron (B), sulphur (S) and gallium (Ga) improves the binding of CH to 2.75, 6.1 and 7.5 times respectively than its values on pristine ZnO-NS. In addition to the CH binding energies falling ideally between physisorption and chemisorption range, a prominent variation in the electronic properties before and after CH exposure indicates the promise of substituted Zn-NS as a useful nano sensors.
由于金属氧化物传感器在环境和工业应用方面的兴趣日益浓厚，本研究提出了甲烷（CH）在最近合成的二维氧化锌形式 ZnO 纳米片（ZnO-NS）上的传感机制。通过范德华修正的第一性原理计算，计算出 CH 在原始 ZnO-NS 上的吸附能不足，限制了其作为高效纳米传感器的应用。然而，（O/Zn）空位的产生和 ZnO-NS 中外来掺杂剂的取代极大地增强了 CH 的结合能。通过综合的能量分析，可以观察到，在所有取代物中，硼（B）、硫（S）和镓（Ga）分别将 CH 的结合能提高了 2.75、6.1 和 7.5 倍，高于其在原始 ZnO-NS 上的值。除了 CH 结合能理想地介于物理吸附和化学吸附之间外，CH 暴露前后电子特性的显著变化表明，取代的 Zn-NS 有望成为有用的纳米传感器。
