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Ultrahigh-sensitive mixed-potential ammonia sensor using dual-functional NiWO4 electrocatalyst for exhaust environment monitoring
- Source :
- Journal of Hazardous Materials. 403:123797
- Publication Year :
- 2021
- Publisher :
- Elsevier BV, 2021.
-
Abstract
- The exhaust monitoring for in-situ quantification of gas pollutants has always been a challenge due to the harsh thermo-chemical environments, for which the solid-electrolyte based gas sensors appear as a realistic solution. In this work, an ultrahigh-sensitive mixed-potential ammonia sensor was developed using a new dual-functional NiWO4 electrocatalyst, synthesized through a low-temperature molten-salt synthesis route. The electrode morphology and diffusion lengths were tuned for optimum performance. The sensor operated at 550 ℃ displayed response of −100 mV to 80 ppm NH3, with response/recovery times of 28/68 s and a record-high sensitivity of 90 mV/decade. Besides, it displayed excellent selectivity and trace-level NH3 detection ability upto 400 ppb. While examining the sensing mechanism, the sensor exhibited an NH3 concentration-dependent transformation of rate-determining kinetics from charge-transfer limited Butler-Volmer type to diffusional mass-transport limited reaction kinetics. Moreover, the remarkable long-term stability with negligible response degradation (
- Subjects :
- 021110 strategic, defence & security studies
Environmental Engineering
Materials science
Health, Toxicology and Mutagenesis
Diffusion
Kinetics
0211 other engineering and technologies
02 engineering and technology
010501 environmental sciences
Electrocatalyst
01 natural sciences
Pollution
Electrochemical gas sensor
Ammonia
chemistry.chemical_compound
chemistry
Chemical engineering
Electrode
Environmental Chemistry
Degradation (geology)
Selectivity
Waste Management and Disposal
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 03043894
- Volume :
- 403
- Database :
- OpenAIRE
- Journal :
- Journal of Hazardous Materials
- Accession number :
- edsair.doi...........361d8e160ad9f7abf24af80e3229166d