Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, Place Croix du Sud 1 (NAPS-ETSF-Boltzmann), 1348 Louvain-la-Neuve, Belgium.
ACS Nano. 2011 Jun 28;5(6):4592-9. doi: 10.1021/nn200294h. Epub 2011 May 13.
The sensing properties of carbon nanotubes (CNTs) decorated with gold nanoparticles have been investigated by means of combined theoretical and experimental approaches. On one hand, first-principles and nonequilibrium Green's functions techniques give access to the microscopic features of the sensing mechanisms in individual nanotubes, such as electronic charge transfers and quantum conductances. On the other hand, drop coating deposition of carbon nanotubes decorated with gold nanoparticles onto sensor substrates and their characterization in the detection of pollutants such as NO(2), CO, and C(6)H(6) provide insight into the sensing ability of nanotube mats. Using the present combined approaches, the improvement in the detection of some specific gases (NO(2) and CO) using Au-functionalized nanotubes is explained. However, for other gases such as C(6)H(6), the Au nanoparticles do not seem to play a crucial role in the sensing process when compared with pristine CNTs functionalized with oxygen plasma. Indeed, these different situations can be explained by identifying the relationship between the change of resistance (macroscopic feature) and the shift of the Fermi level (microscopic feature) after gas adsorption. The understanding of the sensing ability at the atomic level opens the way to design new gas sensors and to tune their selectivity by predicting the nature of the metal that is the most appropriate to detect specific molecular species.
通过理论和实验相结合的方法研究了金纳米粒子修饰的碳纳米管（CNT）的传感性能。一方面，第一性原理和非平衡格林函数技术可以深入了解单个碳纳米管中传感机制的微观特征，如电子电荷转移和量子电导。另一方面，将金纳米粒子修饰的碳纳米管通过滴涂沉积在传感器基底上，并对其在检测 NO(2)、CO 和 C(6)H(6)等污染物方面的性能进行了表征，这为碳纳米管基片的传感能力提供了深入的了解。使用本研究中的综合方法，可以解释 Au 功能化碳纳米管在检测某些特定气体（NO(2)和 CO）方面的性能得到改善。然而，对于其他气体（如 C(6)H(6)），与氧等离子体功能化的原始 CNT 相比，Au 纳米粒子在传感过程中似乎并没有起到关键作用。事实上，通过识别气体吸附后电阻变化（宏观特征）与费米能级移动（微观特征）之间的关系，可以解释这些不同的情况。在原子水平上对传感能力的理解为设计新型气体传感器和通过预测最适合检测特定分子种类的金属的性质来调整其选择性开辟了道路。
