Yadav Ram Manohar, Wu Jingjie, Kochandra Raji, Ma Lulu, Tiwary Chandra Sekhar, Ge Liehui, Ye Gonglan, Vajtai Robert, Lou Jun, Ajayan Pulickel M
†Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
‡Department of Physics, VSSD College, Kanpur, 208002, India.
ACS Appl Mater Interfaces. 2015 Jun 10;7(22):11991-2000. doi: 10.1021/acsami.5b02032. Epub 2015 May 26.
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.
氧还原和析氧反应对于诸如燃料电池、金属空气电池以及通过水分解制氢等广泛的可再生能源技术至关重要，因此，人们已经付出巨大努力来开发用于这些反应的优异催化剂。然而，开发用于这两种反应的具有成本效益且高效的双功能催化剂仍然是一个巨大挑战。在此，我们报道了通过使用不同含氮前驱体的液相化学气相沉积技术合成的具有不同直径分布的竹状碳氮纳米管（CNNTs）的电催化研究。这些CNNTs被发现是用于氧还原和析氧反应的高效双功能电催化剂。电催化活性强烈依赖于纳米管直径以及氮官能团类型。直径较大的CNNTs对这些反应更有利。纳米管直径的增加本身通过降低氧吸附能、提高导电性来增强催化活性，并通过增加CNNTs中催化活性氮部分的百分比进一步促进反应。
