Development of three dimensional graphene based high sensitivity gas sensor

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14174
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: University of Tsukuba
• Principal Investigator: Ito Yoshikazu 筑波大学, 数理物質系, 准教授 (90700170)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: グラフェン / ガスセンサー / 水素 / 二酸化炭素 / 多孔質構造 / 分子吸着

Outline of Final Research Achievements

It is revealed that detection mechanisms of hydrogen molecules under hydrogen gas flowing conditions based on monolithic 3D nanoporous reduced graphene oxide at room temperature. The nanoporous reduced graphene oxide increases the molecular physisorption of hydrogen molecules without any catalytic metals or heating due to the dramatically increased surface area in comparison to the 2D graphene sheet and conventional reduced graphene oxide flakes. It was found that two different behaviors of resistance change that the resistance decreases due to charge transfer from the hydrogen molecules to the reduced graphene oxide at concentrations of adsorbed hydrogen molecules lower than 2.8 ppm, and conversely the resistance increases due to Coulomb scattering effects at concentrations of adsorbed hydrogen molecules exceeding 5.0 ppm, which is supported by density functional theory. These findings provide the development of catalyst free and non-heated physisorption-type molecular detection.

Free Research Field

グラフェン

Academic Significance and Societal Importance of the Research Achievements

可燃性ガスを検出するために着火の恐れがあるような危険なセンシングをするのは本末転倒である。本研究は膨大な表面積総量を持つ多孔質グラフェンを採用しその表面に可燃性ガス分子を物理吸着させることによって室温かつ化学反応を起こさない気流下でのガス吸着センサーの提案をしている。特に水素は無極性分子であるため化学反応を伴うセンサーが主流である。燃料電池車や水素ステーションの安全性確保に向けて不慮の事故があっても着火の恐れが無い非加熱式水素ガスセンサーが開発できれば水素社会への貢献が期待される。このような着眼点で非加熱式ガスセンサーは安全な労働環境を実現する炭素材料系ガスセンサーの開発方針への貢献ができる。