title: Room temperature CO and H2 sensing with carbon nanoparticles.
abstract: We report on a shell-shaped carbon nanoparticle (SCNP)-based gas sensor that reversibly detects reducing gas molecules such as CO and H(2)  at room temperature both in air and inert atmosphere. Crystalline SCNPs were synthesized by laser-assisted reactions in pure acetylene gas flow, chemically treated to obtain well-dispersed SCNPs and then patterned on a substrate by the ion-induced focusing method. Our chemically functionalized SCNP-based gas sensor works for low concentrations of CO and H(2)  at room temperature even without Pd or Pt catalysts commonly used for splitting H(2)  molecules into reactive H atoms, while metal oxide gas sensors and bare carbon-nanotube-based gas sensors for sensing CO and H(2)  molecules can operate only at elevated temperatures. A pristine SCNP-based gas sensor was also examined to prove the role of functional groups formed on the surface of functionalized SCNPs. A pristine SCNP gas sensor showed no response to reducing gases at room temperature but a significant response at elevated temperature, indicating a different sensing mechanism from a chemically functionalized SCNP sensor.
authors: Division of WCU Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Korea.
authors: Daegyu
authors: D
authors: Kim
authors: Peter V
authors: PV
authors: Pikhitsa
authors: Hongjoo
authors: H
authors: Yang
authors: Mansoo
authors: M
authors: Choi
mesh_terms: D000114:Acetylene; D000336:Aerosols; D002244:Carbon / Q000737:chemistry*; D002248:Carbon Monoxide / Q000032:analysis* / Q000737:chemistry; D006859:Hydrogen / Q000032:analysis* / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D053260:Soot; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: D000336:Aerosols; D053260:Soot; D002244:Carbon; D002248:Carbon Monoxide; D006859:Hydrogen; D000114:Acetylene