In Situ Formation of Nitrogen-Doped CNTs from Liquid Precursor for Improving Oxygen Reduction Activity

Nitrogen-doped carbon nanotubes (N-CNTs) present significant advantages in energy applications; however, their incorporation into functional systems remains challenging, primarily due to issues such as pronounced agglomeration and insufficient interfacial interactions with host materials. In this study, we present a versatile in situ growth strategy for N-CNTs using a liquid-phase precursor and silica nanospheres as sacrificial templates. The silica nanospheres are demonstrated to play a pivotal role in promoting the controlled growth of N-CNTs during the pyrolysis of an ionic liquid, thereby effectively mediating the composition and structural evolution of the resulting carbon material. This method achieves a nitrogen doping content of 5.5 wt%, predominantly consisting of pyridinic-N and pyrrolic-N species, and a specific surface area of 698.7 m² g–1, both of which contribute to significantly enhanced oxygen reduction reaction (ORR) electrocatalytic activity under alkaline conditions. The proposed strategy offers a scalable and facile route for integrating N-CNTs into carbon-based electrocatalysts, providing significant potential for advanced applications in fuel cells and metal-air batteries.