Dilonardo Elena, Penza Michele, Alvisi Marco, Rossi Riccardo, Cassano Gennaro, Di Franco Cinzia, Palmisano Francesco, Torsi Luisa, Cioffi Nicola
Department of Chemistry, Università degli Studi di Bari Aldo Moro, Bari, Italy; Department of Electrotechnics and Electronics, Politecnico di Bari, Bari, Italy.
Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Laboratory Functional Materials and Technologies for Sustainable Applications - Brindisi Research Center, Brindisi, Italy.
Beilstein J Nanotechnol. 2017 Mar 10;8:592-603. doi: 10.3762/bjnano.8.64. eCollection 2017.
Multiwalled carbon nanotube (MWCNT)-based chemiresistors were electrochemically decorated with Au and Pd nanoparticles (NPs), resulting in an improvement in the detection of gaseous pollutants as compared to sensors based on pristine MWCNTs. Electrophoresis was used to decorate MWCNTs with preformed Au or Pd NPs, thus preserving their nanometer-sized dimensions and allowing the metal content to be tuned by simply varying the deposition time. The sensing response of unmodified and metal-decorated MWCNTs was evaluated towards different gaseous pollutants (e.g., NO, HS, NH and CH) at a wide range of concentrations in the operating temperature range of 45-200 °C. The gas sensing results were related to the presence, type and loading of metal NPs used in the MWCNT functionalization. Compared to pristine MWCNTs, metal-decorated MWCNTs revealed a higher gas sensitivity, a faster response, a better stability, reversibility and repeatability, and a low detection limit, where all of these sensing properties were controlled by the type and loading of the deposited metal catalytic NPs. Specifically, in the NO gas sensing experiments, MWCNTs decorated with the lowest Au content revealed the highest sensitivity at 150 °C, while MWCNTs with the highest Pd loading showed the highest sensitivity when operated at 100 °C. Finally, considering the reported gas sensing results, sensing mechanisms have been proposed, correlating the chemical composition and gas sensing responses.
基于多壁碳纳米管（MWCNT）的化学电阻器用电化学方法用金和钯纳米颗粒（NP）进行修饰，与基于原始MWCNT的传感器相比，气态污染物的检测得到了改善。采用电泳法用预先形成的金或钯纳米颗粒修饰MWCNT，从而保持其纳米尺寸，并通过简单改变沉积时间来调节金属含量。在45-200°C的工作温度范围内，评估了未修饰和金属修饰的MWCNT对不同气态污染物（如NO、HS、NH和CH）在广泛浓度范围内的传感响应。气敏结果与MWCNT功能化中使用的金属纳米颗粒的存在、类型和负载量有关。与原始MWCNT相比，金属修饰的MWCNT具有更高的气敏性、更快的响应速度、更好的稳定性、可逆性和重复性以及低检测限，所有这些传感特性均由沉积的金属催化纳米颗粒的类型和负载量控制。具体而言，在NO气敏实验中，金含量最低修饰的MWCNT在150°C时显示出最高的灵敏度，而钯负载量最高的MWCNT在100°C下工作时显示出最高的灵敏度。最后，考虑到所报道的气敏结果，提出了传感机制，将化学成分和气敏响应联系起来。
