Enhanced High-Temperature (600 °C) NO2 Response of ZnFe2O4 Nanoparticle-Based Exhaust Gas Sensors

Nanomaterials

Adeel Afzal¹  Naseer Iqbal¹  UmairYaqub Qazi¹  Adnan Mujahid²  Rahat Javaid³ 

[1] 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;Renewable Energy Research Center, Fukushima Renewable Energy Institute, National Institute of Advanced Industrial Science and Technology, AIST, 2-2-9 Machiikedai, Koriyama, Fukushima 963-0298, Japan;

关键词: annealing temperature;    chemiresistors;    gas sensors;    oxygen vacancies;    sensing mechanism;    ZnFe₂O₄ nanoparticles;   

DOI  :  10.3390/nano10112133

来源: DOAJ

【 摘 要 】

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 NO₂ gas at 600 °C. The sensing element consists of ZnFe₂O₄ 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 ZnFe₂O₄ nanoparticles are studied. A mixed spinel structure of ZnFe₂O₄ nanoparticles with a lattice parameter of 8.445 Å is revealed by X-ray diffraction analysis. The crystallite size and X-ray density of ZnFe₂O₄ nanoparticles increase with the annealing temperature, whereas the lattice parameter and volume are considerably reduced indicating lattice distortion and defects such as oxygen vacancies. ZnFe₂O₄ nanoparticles annealed at 1000 °C exhibit the highest sensitivity (0.13% ppm^–1), sharp response (τ_res = 195 s), recovery (τ_rec = 17 s), and linear response to 100–400 ppm NO₂ gas. The annealing temperature and oxygen vacancies play a major role in determining the sensitivity of devices. The plausible sensing mechanism is discussed. ZnFe₂O₄ nanoparticles show great potential for high-temperature exhaust gas sensing applications.

【 授权许可】

Unknown