Novel approaches for highly selective, room-temperature gas sensors based on atomically dispersed non-precious metals

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2020-12, Vol.8 (45), p.23784-23794
• Main Authors: Tian, Renbing, Wang, Shiyan, Hu, Xuefeng, Zheng, Jian-Guo, Ji, Peng, Lin, Jun, Zhang, Jing, Xu, Mingjie, Bao, Jun, Zuo, Shouwei, Zhang, Hui, Zhang, Wei, Wang, Jinlan, Yu, Liandong
• Format: Article
• Language: English
• Subjects: Atom economy; Density functional theory; Dispersion; Fine structure; Gas sensors; Gases; Mathematical analysis; Metals; Mossbauer spectroscopy; Nitrogen dioxide; Room temperature; Scanning transmission electron microscopy; Sensors; Spectroscopy; Spectrum analysis; Technology; Transmission electron microscopy; Ultrastructure; X ray absorption
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d0ta05775d

Atomically dispersed (AD) materials have incredible catalytic ability and offer atom economy with 100% metal utilization during catalytic reactions. Herein, we report the first attempt to synthesize AD FeNC materials for use as highly selective, room-temperature gas sensors. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM), extended X-ray absorption fine structure (EXAFS) spectroscopy, and Mössbauer spectroscopy characterization methods confirm the existence of atomically dispersed Fe with an FeN 4 coordination. We demonstrate a room temperature, sensitive, and selective NO 2 gas sensor technology using this platform, offering significant advantages over existing technology. Density functional theory (DFT) calculations verify that electrons are transferred to NO 2 from FeN 4 during NO 2 adsorption. Both DFT calculations and experiments also reveal that the barrier for NO 2 decomposition by AD FeNC is 0.73 eV, which is significantly lower than previously reported barriers (2.60-3.54 eV) in other materials. Such unique catalytic properties combined with a high surface affinity for NO 2 molecules enable AD FeNC gas sensors to have excellent selective NO 2 detection at room temperature. The method proposed here can inspire the use of AD materials to detect other gases and catalyze similar novel developments in the gas sensor industry. Atomically dispersed (AD) materials have incredible catalytic ability and offer atom economy with 100% metal utilization during catalytic reactions.