Enhanced Sensitivity and Stability of Room-Temperature NH3 Sensors Using Core鈥揝hell CeO2 Nanoparticles@Cross-linked PANI with p鈥搉 Heterojunctions

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• 作者：Lingling Wang ; Hui Huang ; Songhua Xiao ; Daoping Cai ; Yuan Liu ; Bin Liu ; Dandan Wang ; Chenxia Wang ; Han Li ; Yanrong Wang ; Qiuhong Li ; Taihong Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：August 27, 2014
• 年：2014
• 卷：6
• 期：16
• 页码：14131-14140
• 全文大小：699K
• ISSN：1944-8252

文摘

We report a room-temperature NH₃ gas sensor with high response and great long-term stability, including CeO₂ NPs conformally coated by cross-linked PANI hydrogel. Such core鈥搒hell nanocomposites were prepared by in situ polymerization with different weight ratios of CeO₂ NPs and aniline. At room temperature, the nanohybrids showed enhanced response (6.5 to 50 ppm of NH₃), which could be attributed to p鈥搉 junctions formed by the intimate contact between these two materials. Moreover, the stability was discussed in terms of phytic acid working as a gelator, which helped the PANI sheath accommodate itself and enhance the mechanical strength and chemical stability of the sensors by avoiding 鈥渟welling effect鈥?in high relative humidity. The sensors maintained its sensing characteristic (response of ca. 6.5 to 50 ppm of NH₃) in 15 days. Herein, the obtained results could help to accelerate the development of ammonia gas sensor.

Keywords:

CeO₂ NPs; PANI hydrogel; NH₃ sensor; p鈭抧 junction; phytic acid; core鈭抯hell