A simple synthesis of nitrogen-doped carbon micro- and nanotubes.

Nitrogen-doped carbon nanotubes (N-CNTs) have shown promising performance in a variety of applications: catalysts, catalyst supports, lithium-ion batteries and supercapacitors. While chemical vapor deposition continues to be the most common method for N-CNT fabrication, its complexity and high cost have prevented the practical implementation of N-CNTs on a larger scale. Here, we describe a new and simple method for N-CNT synthesis. This method is not only potentially scalable to any required level but also allows for the control of the tube size (20-1000 nm in diameter) and nitrogen doping levels (4-9 at%) through the selection of most suitable transition metal and heat-treatment conditions.