title: Carbon Nitrogen Nanotubes as Efficient Bifunctional Electrocatalysts for Oxygen Reduction and Evolution Reactions.
abstract: Oxygen reduction and evolution reactions are essential for broad range of renewable energy technologies such as fuel cells, metal-air batteries and hydrogen production through water splitting, therefore, tremendous effort has been taken to develop excellent catalysts for these reactions. However, the development of cost-effective and efficient bifunctional catalysts for both reactions still remained a grand challenge. Herein, we report the electrocatalytic investigations of bamboo-shaped carbon nitrogen nanotubes (CNNTs) having different diameter distribution synthesized by liquid chemical vapor deposition technique using different nitrogen containing precursors. These CNNTs are found to be efficient bifunctional electrocatalyst for oxygen reduction and evolution reactions. The electrocatalytic activity strongly depends on the nanotube diameter as well as nitrogen functionality type. The higher diameter CNNTs are more favorable for these reactions. The increase in nanotube diameter itself enhances the catalytic activity by lowering the oxygen adsorption energy, better conductivity, and further facilitates the reaction by increasing the percentage of catalytically active nitrogen moieties in CNNTs.
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.|‡Department of Physics, VSSD College, Kanpur, 208002, India.
authors.forename: Ram Manohar
authors.initials: RM
authors.lastname: Yadav
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Jingjie
authors.initials: J
authors.lastname: Wu
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Raji
authors.initials: R
authors.lastname: Kochandra
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Lulu
authors.initials: L
authors.lastname: Ma
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Chandra Sekhar
authors.initials: CS
authors.lastname: Tiwary
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Liehui
authors.initials: L
authors.lastname: Ge
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Gonglan
authors.initials: G
authors.lastname: Ye
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Vajtai
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Lou
authors.affiliation: †Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan
keywords: carbon nitrogen nanotubes; nanotube diameter; nitrogen moieties; oxygen reduction and evolution reactions