Improvement of H2S Sensing Properties of SnO2-Based Thick Film Gas Sensors Promoted with MoO3 and NiO

Sensors

Soo Chool Lee⁴  Seong Yeol Kim⁴  Byung Wook Hwang⁴  Suk Yong Jung⁴  Dhanusuraman Ragupathy²  In Sung Son³  Duk Dong Lee¹ 

[1] School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu 702-701, Korea; E-Mail:;Centre for Research & Development, PRIST University, Puducherry 605 007, India; E-Mail:;HKC, Sucho-gu, Seoul 130-070, Korea; E-Mail:;Department of Chemical Engineering, Kyungpook National University, Daegu 702-701, Korea; E-Mails:

关键词: sensor;    SnO₂;    pore size;    H₂S;    MoO₃;    NiO;   

DOI  :  10.3390/s130303889

来源: mdpi

【 摘 要 】

The effects of the SnO₂ pore size and metal oxide promoters on the sensing properties of SnO₂-based thick film gas sensors were investigated to improve the detection of very low H₂S concentrations (<1 ppm). SnO₂ sensors and SnO₂-based thick-film gas sensors promoted with NiO, ZnO, MoO₃, CuO or Fe₂O₃ were prepared, and their sensing properties were examined in a flow system. The SnO₂ materials were prepared by calcining SnO₂ at 600, 800, 1,000 and 1,200 °C to give materials identified as SnO₂(600), SnO₂(800), SnO₂(1000), and SnO₂(1200), respectively. The Sn(12)Mo5Ni3 sensor, which was prepared by physically mixing 5 wt% MoO₃ (Mo5), 3 wt% NiO (Ni3) and SnO₂(1200) with a large pore size of 312 nm, exhibited a high sensor response of approximately 75% for the detection of 1 ppm H₂S at 350 °C with excellent recovery properties. Unlike the SnO₂ sensors, its response was maintained during multiple cycles without deactivation. This was attributed to the promoter effect of MoO₃. In particular, the Sn(12)Mo5Ni3 sensor developed in this study showed twice the response of the Sn(6)Mo5Ni3 sensor, which was prepared by SnO₂(600) with the smaller pore size than SnO₂(1200). The excellent sensor response and recovery properties of Sn(12)Mo5Ni3 are believed to be due to the combined promoter effects of MoO₃ and NiO and the diffusion effect of H₂S as a result of the large pore size of SnO₂.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.