A limiting current hydrogen sensor based on BaHf0.8Fe0.2O3-δ dense diffusion barrier and BaHf0.7Sn0.1In0.2O3-δ protonic conductor. Issue 15 (1st August 2022)

• Record Type: Journal Article
• Authors: Yang, Wenjie; Wang, Ling; Li, Yuehua; Zhou, Huizhu; He, Zhangxing; Liu, Honghao; Dai, Lei
• Is Part Of: Ceramics international. Volume 48:Issue 15(2022)
• Page Start: 22113
• Page End: 22123
• Publication Date: 2022-08-01
• Subjects: BaHf0.8Fe0.2O3-δ dense diffusion barrier -- Limiting current hydrogen sensor -- Co-pressing and co-sintering -- BaHf0.7Sn0.1In0.2O3-δ proton conductor; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.04.199
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: A limiting current hydrogen sensor was successfully prepared by the co-pressing and co-sintering method using proton-electron mixed conductor BaHf0.8 Fe0.2 O3-δ as the dense diffusion barrier instead for small hole and BaHf0.7 Sn0.1 In0.2 O3-δ as proton conducting electrolyte. The BaHf0.8 Fe0.2 O3-δ and BaHf0.7 Sn0.1 In0.2 O3-δ powders were synthesized by high temperature solid state method. The phase composition, microstructure, chemical stability and conductivity of materials were characterized. Sensing performance of the hydrogen sensor was tested. The results show that dense BaHf0.8 Fe0.2 O3-δ and BaHf0.7 Sn0.1 In0.2 O3-δ layer are closely combined together by the co-pressing and co-sintering technique at 1600 °C for 8 h and clear boundaries are observed between two pure perovskite phases. BaHf0.8 Fe0.2 O3-δ shows excellent chemical stability for pure H2 and CO2, water steam and 200 ppm H2 S/Ar. Meanwhile, as the dense diffusion barrier, BaHf0.8 Fe0.2 O3-δ possesses considerable proton and electron conductivity compared with small hole. The sensor shows a stable limiting current platform in 0–600 ppm H2 at 400–600 °C at a certain voltage range due to dense BaHf0.8 Fe0.2 O3-δ layer forming diffusion control. The limiting current (ΔIL ) has a good linear dependence on the hydrogen concentration. In addition, there is a good linear relationship between log(IL T) and 1000/T, and the Arrhenius model of limiting current is log(IL T) = 6.21-4.96 × 1000/T, and the hydrogen diffusion activation energy is 0.98 eV. The sensor has good long-term stability and high anti-interference capability to O2, CO2 or H2 S, but water vapor has a certain effect on sensing performance.