中国物理B ›› 2022, Vol. 31 ›› Issue (2): 28101-028101.doi: 10.1088/1674-1056/ac1336

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SnO2/Co3O4 nanofibers using double jets electrospinning as low operating temperature gas sensor

Zhao Wang(王昭), Shu-Xing Fan(范树兴), and Wei Tang(唐伟)   

  1. School of Physics and Electronics, Shandong Normal University, Jinan 250358, China
  • 收稿日期:2021-04-25 修回日期:2021-06-28 接受日期:2021-07-12 出版日期:2022-01-13 发布日期:2022-01-18
  • 通讯作者: Wei Tang E-mail:tangweiyouxiang@foxmail.com

SnO2/Co3O4 nanofibers using double jets electrospinning as low operating temperature gas sensor

Zhao Wang(王昭), Shu-Xing Fan(范树兴), and Wei Tang(唐伟)   

  1. School of Physics and Electronics, Shandong Normal University, Jinan 250358, China
  • Received:2021-04-25 Revised:2021-06-28 Accepted:2021-07-12 Online:2022-01-13 Published:2022-01-18
  • Contact: Wei Tang E-mail:tangweiyouxiang@foxmail.com

摘要: SnO2/Co3O4 nanofibers (NFs) are synthesized by using a homopolar electrospinning system with double jets of positive polarity electric fields. The morphology and structure of SnO2/Co3O4 hetero-nanofibers are characterized by using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectrometer (XPS). The analyses of SnO2/Co3O4 NFs by EDS and HRTEM show that the cobalt and tin exist on one nanofiber, which is related to the homopolar electrospinning and the crystallization during sintering. As a typical n-type semiconductor, SnO2 has the disadvantages of high optimal operating temperature and poor reproducibility. Comparing with SnO2, the optimal operating temperature of SnO2/Co3O4 NFs is reduced from 350℃ to 250℃, which may be related to the catalysis of Co3O4. The response of SnO2/Co3O4 to 100-ppm ethanol at 250℃ is 50.9, 9 times higher than that of pure SnO2, which may be attributed to the p-n heterojunction between the n-type SnO2 crystalline grain and the p-type Co3O4 crystalline grain. The nanoscale p-n heterojunction promotes the electron migration and forms an interface barrier. The synergy effects between SnO2 and Co3O4, the crystalline grain p-n heterojunction, the existence of nanofibers and the large specific surface area all jointly contribute to the improved gas sensing performance.

关键词: SnO2/Co3O4 nanofibers (NFs), homopolar double jets electrospinning, gas sensors, nanoscale p-n heterojunction

Abstract: SnO2/Co3O4 nanofibers (NFs) are synthesized by using a homopolar electrospinning system with double jets of positive polarity electric fields. The morphology and structure of SnO2/Co3O4 hetero-nanofibers are characterized by using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectrometer (XPS). The analyses of SnO2/Co3O4 NFs by EDS and HRTEM show that the cobalt and tin exist on one nanofiber, which is related to the homopolar electrospinning and the crystallization during sintering. As a typical n-type semiconductor, SnO2 has the disadvantages of high optimal operating temperature and poor reproducibility. Comparing with SnO2, the optimal operating temperature of SnO2/Co3O4 NFs is reduced from 350℃ to 250℃, which may be related to the catalysis of Co3O4. The response of SnO2/Co3O4 to 100-ppm ethanol at 250℃ is 50.9, 9 times higher than that of pure SnO2, which may be attributed to the p-n heterojunction between the n-type SnO2 crystalline grain and the p-type Co3O4 crystalline grain. The nanoscale p-n heterojunction promotes the electron migration and forms an interface barrier. The synergy effects between SnO2 and Co3O4, the crystalline grain p-n heterojunction, the existence of nanofibers and the large specific surface area all jointly contribute to the improved gas sensing performance.

Key words: SnO2/Co3O4 nanofibers (NFs), homopolar double jets electrospinning, gas sensors, nanoscale p-n heterojunction

中图分类号:  (Methods of micro- and nanofabrication and processing)

  • 81.16.-c
81.07.-b (Nanoscale materials and structures: fabrication and characterization) 85.35.-p (Nanoelectronic devices)