Afzal Adeel, Mujahid Adnan, Iqbal Naseer, Javaid Rahat, Qazi Umair Yaqub
Department of Chemistry, College of Science, University of Hafr Al Batin, P.O. Box 1803, Hafr Al Batin 39524, Saudi Arabia.
Institute of Chemistry, University of Punjab, Quaid-i-Azam Campus, Lahore 54590, Pakistan.
Nanomaterials (Basel). 2020 Oct 27;10(11):2133. doi: 10.3390/nano10112133.
Fabrication of gas sensors to monitor toxic exhaust gases at high working temperatures is a challenging task due to the low sensitivity and narrow long-term stability of the devices under harsh conditions. Herein, the fabrication of a chemiresistor-type gas sensor is reported for the detection of NO gas at 600 °C. The sensing element consists of ZnFeO nanoparticles prepared via a high-energy ball milling and annealed at different temperatures (600-1000 °C). The effects of annealing temperature on the crystal structure, morphology, and gas sensing properties of ZnFeO nanoparticles are studied. A mixed spinel structure of ZnFeO nanoparticles with a lattice parameter of 8.445 Å is revealed by X-ray diffraction analysis. The crystallite size and X-ray density of ZnFeO nanoparticles increase with the annealing temperature, whereas the lattice parameter and volume are considerably reduced indicating lattice distortion and defects such as oxygen vacancies. ZnFeO nanoparticles annealed at 1000 °C exhibit the highest sensitivity (0.13% ppm), sharp response ( = 195 s), recovery ( = 17 s), and linear response to 100-400 ppm NO gas. The annealing temperature and oxygen vacancies play a major role in determining the sensitivity of devices. The plausible sensing mechanism is discussed. ZnFeO nanoparticles show great potential for high-temperature exhaust gas sensing applications.
由于在苛刻条件下器件的灵敏度低且长期稳定性窄，制造用于在高工作温度下监测有毒废气的气体传感器是一项具有挑战性的任务。在此，报道了一种用于在600℃检测NO气体的化学电阻型气体传感器的制造。传感元件由通过高能球磨制备并在不同温度（600-1000℃）下退火的ZnFeO纳米颗粒组成。研究了退火温度对ZnFeO纳米颗粒的晶体结构、形态和气体传感性能的影响。通过X射线衍射分析揭示了晶格参数为8.445 Å的ZnFeO纳米颗粒的混合尖晶石结构。ZnFeO纳米颗粒的微晶尺寸和X射线密度随退火温度的升高而增加，而晶格参数和体积则显著减小，表明存在晶格畸变和诸如氧空位的缺陷。在1000℃退火的ZnFeO纳米颗粒表现出最高的灵敏度（0.13% ppm）、快速响应（ = 195 s）、恢复（ = 17 s）以及对100-400 ppm NO气体的线性响应。退火温度和氧空位在决定器件的灵敏度方面起主要作用。讨论了合理的传感机制。ZnFeO纳米颗粒在高温废气传感应用中显示出巨大潜力。
