Liu Wei, Gu Ding, Li Xiaogan
School of Microelectronics, Key Laboratory of Liaoning for Integrated Circuits Technology, Dalian University of Technology, Dalian, Liaoning 116024, P. R. China.
ACS Appl Mater Interfaces. 2021 May 5;13(17):20336-20348. doi: 10.1021/acsami.1c02500. Epub 2021 Apr 26.
A novel chemiresistive-type sensor for detecting sub-ppm NO has been fabricated using AuPt bimetal-decorated SnSe microflowers, which was synthesized by the hydrothermal treatment followed by in situ chemical reduction of the bimetal precursors on the surface of the petals of the microflowers. The as-prepared sensor registers a superior performance in detection of sub-ppm concentration of NO. Functionalized by the AuPt bimetal, the SnSe microflower-based sensor shows a response of approximately 4.62 to 8 ppm NO at 130 °C. It is significantly higher than those of the sensors using the pristine SnSe (∼2.29) and the modified SnSe samples by a single metal, either Au (∼3.03) or Pt (∼3.97). The sensor demonstrates excellent long-term stability, signal repeatability, and selectivity to some typical interfering gaseous species including ammonia, acetone, formaldehyde, ethanol, methanol, benzene, CO, SO, and CO. The remarkable improvement of the sensitive characteristics could be induced by the electronic and chemical sensitization and the synergistic effect of the AuPt bimetal. Density functional theory (DFT) is implemented to calculate the adsorption states of NO on the sensing materials and thus to possibly reveal the sensing mechanism. The significantly enhanced response of the SnSe-based sensor decorated with AuPt bimetallic nanoparticles has been found to be possibly caused by the orbital hybridization of O, Au, and Pt atoms leading to the redistribution of electrons, which is beneficial for NO molecules to obtain more electrons from the composite material.
一种用于检测亚ppm级一氧化氮（NO）的新型化学电阻型传感器已通过金铂双金属修饰的硒化锡（SnSe）微花制备而成，该微花是通过水热法合成，随后在微花花瓣表面原位化学还原双金属前驱体得到的。所制备的传感器在检测亚ppm浓度的NO方面表现出优异的性能。基于SnSe微花的传感器经金铂双金属功能化后，在130℃时对8 ppm的NO显示出约4.62的响应。这显著高于使用原始SnSe（约2.29）以及用单一金属（金约3.03或铂约3.97）修饰的SnSe样品的传感器的响应。该传感器对包括氨、丙酮、甲醛、乙醇、甲醇、苯、一氧化碳（CO）、二氧化硫（SO）和二氧化碳（CO₂）等一些典型干扰气体物种表现出优异的长期稳定性、信号重复性和选择性。敏感特性的显著改善可能是由金铂双金属的电子和化学敏化以及协同效应引起的。采用密度泛函理论（DFT）计算NO在传感材料上的吸附状态，从而可能揭示传感机制。已发现用金铂双金属纳米粒子修饰的基于SnSe的传感器响应显著增强，这可能是由于氧、金和铂原子的轨道杂化导致电子重新分布，有利于NO分子从复合材料中获得更多电子。
