P- and PN-Doped Nanotubes for Ultrasensitive and Selective Molecular Detection

Journal Article · Wed Dec 01 04:00:00 EST 2010 · Nanoscale

OSTI ID:1007829

Cruz Silva, Eduardo ^[1]; Terrones Maldonado, Humberto ^[1]; Terrones Maldonado, Mauricio ^[1]; Charlier, Jean Christophe ^[2]; Meunier, Vincent ^[1]; Sumpter, Bobby G. ^[1]; Munoz-Sandoval, Emilio ^[3]; Lopez, Florentino ^[3]

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1. ORNL
2. Universite catholique de Louvain (UCL), Belgium
3. IPICyT

A first-principles approach is used to establish that substitutional phosphorus atoms strongly modify the chemical properties of the surface of carbon nanotubes, creating highly-localized sites with specific affinity towards acceptor molecules. Phosphorus-nitrogen co-dopants have a similar effect for acceptor molecules, but the P-N bond can also accept charge, resulting in affinity towards donor molecules. This molecular selectivity is illustrated in CO and NH3 adsorbed on PN doped nanotubes, O2 on P-doped nanotubes, and NO2 and SO2 on both P- and PN-doped nanotubes. The adsorption of different chemical species onto the doped nanotubes modifies the dopant-induced localized states, which subsequently alter electronic conductance. Although SO2 and CO adsorption cause minor shifts in electronic conductance; NH3, NO2, and O2 adsorptions induce the suppression of a conductance dip. Conversely, the adsorption of NO2 on PN-doped nanotubes is accompanied with the appearance of an additional dip in conductance, correlated with a shift of the existing ones. Overall these changes in electric conductance provide an efficient way to detect selectively the presence of specific molecules. Additionally, the high oxidation potential of the P-doped nanotubes makes them good candidates for electrode materials in hydrogen fuel cells.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1007829
• Journal Information: Nanoscale, Journal Name: Nanoscale Journal Issue: N/A Vol. N/A
• Country of Publication: United States
• Language: English