NO2 and CO gas adsorption on carbon nanotubes: Experiment and theory

In this work a combined experimental and theoretical study on carbon nanotube (CNT) based system for gas sensing applications is reported. Carbon nanotubes thin films have been deposited by plasma-enhanced chemical vapor deposition on Si3N4/Si substrates provided with Pt electrodes. Microstructural features as determined by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy highlight the growth of defective tubular carbon structures. The electrical resistivity of the CNT film shows a semiconductinglike temperature dependence and a p-type response with decreasing electrical resistance upon exposure to NO2 gas (100 ppb). No response has been found by exposing the film to CO gas in the temperature range between 25 and 250 °C. In order to obtain a theoretical validation of the experimental results, the equilibrium position, charge transfer, and density of states are calculated from first principles for the CNT+CO and CNT+NO2 systems. Our spin-unrestricted density functional...

[1]  Jose Maria Kenny,et al.  Sensors for sub-ppm NO2 gas detection based on carbon nanotube thin films , 2003 .

[2]  Saroj K. Nayak,et al.  Effect of H2O adsorption on electron transport in a carbon nanotube , 2002 .

[3]  M. Madou,et al.  Chemical Sensing With Solid State Devices , 1989 .

[4]  L. Hedin,et al.  A local exchange-correlation potential for the spin polarized case. i , 1972 .

[5]  S. Xie,et al.  Raman characterization of aligned carbon nanotubes produced by thermal decomposition of hydrocarbon vapor , 1997 .

[6]  Jijun Zhao,et al.  Gas molecule adsorption in carbon nanotubes and nanotube bundles , 2002 .

[7]  Zettl,et al.  Extreme oxygen sensitivity of electronic properties of carbon nanotubes , 2000, Science.

[8]  Kong,et al.  Nanotube molecular wires as chemical sensors , 2000, Science.

[9]  M. S. de Vries,et al.  Cobalt-catalysed growth of carbon nanotubes with single-atomic-layer walls , 1993, Nature.

[10]  B. Delley.  A scattering theoretic approach to scalar relativistic corrections on bonding , 1998 .

[11]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[12]  Daoben Zhu,et al.  Anisotropic Electrical Transport Properties of Aligned Carbon Nanotube Films , 2001 .

[13]  Vincent Bayot,et al.  Electrical resistance of a carbon nanotube bundle , 1994 .

[14]  Saroj K. Nayak,et al.  Towards extending the applicability of density functional theory to weakly bound systems , 2001 .

[15]  M. Nardelli.  A density-functional study of van der Waals forces: He interaction with a semiconductor surface , 1996 .

[16]  Pulsed plasma-induced alignment of carbon nanotubes , 2003 .

[17]  J. Kenny,et al.  Effects of oxygen annealing on gas sensing properties of carbon nanotube thin films , 2003 .

[18]  G. Scoles,et al.  OXYGEN ADSORPTION ON GRAPHITE AND NANOTUBES , 2003 .

[19]  Cohen,et al.  Electronic properties of oxidized carbon nanotubes , 2000, Physical review letters.

[20]  John Robertson,et al.  Growth process conditions of vertically aligned carbon nanotubes using plasma enhanced chemical vapor deposition , 2001 .

[21]  S. Roth,et al.  Electronic transport in carbon nanotube ropes and mats , 1999 .

[22]  Wang,et al.  Accurate and simple analytic representation of the electron-gas correlation energy. , 1992, Physical review. B, Condensed matter.

[23]  A. Johansson,et al.  Charge transport in π-conjugated systems , 2003 .

[24]  Craig A. Grimes,et al.  A wireless, passive carbon nanotube-based gas sensor , 2002 .

[25]  H. Monkhorst,et al.  SPECIAL POINTS FOR BRILLOUIN-ZONE INTEGRATIONS , 1976 .

[26]  B. Delley.  From molecules to solids with the DMol3 approach , 2000 .

[27]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[28]  Angel Rubio,et al.  INTERACTION OF MOLECULAR AND ATOMIC HYDROGEN WITH (5,5) AND (6,6) SINGLE-WALL CARBON NANOTUBES , 2002 .

[29]  Jae Do Lee,et al.  Adsorption of NH3 and NO2 molecules on carbon nanotubes , 2001 .

[30]  John Robertson,et al.  Temperature selective growth of carbon nanotubes by chemical vapor deposition , 2002 .

[31]  L. Forró,et al.  Reactivity of different kinds of carbon during oxidative purification of catalytically prepared carbon nanotubes , 2001 .

[32]  Martel,et al.  Intertube coupling in ropes of single-wall carbon nanotubes , 2000, Physical review letters.

[33]  J. Kenny,et al.  Formation of carbon nanotubes by plasma enhanced chemical vapor deposition: Role of nitrogen and catalyst layer thickness , 2002 .