Engineering and physical science
Heteroatom Doped Porous Carbons for Clean Energy Applications
Activated carbons are an emerging class of porous materials which are extremely versatile in their applications- gas storage/ separation sorbents, oxygen reduction reaction catalysts, and supercapacitor electrodes. Activated carbons feature lightweight, thermal, chemical and physical stability as well as adjustable textural properties. Doping of non-carbon elements into a heteroatom structure to alter specific properties allows fine-tuning of material properties. The most well-established dopant is nitrogen as it induces basicity and charge delocalization into the carbon structure to enhance gas sorption and electrochemical performances. However, a method of incorporating nitrogen into the carbon matrix which is efficient, facile and cost effective has yet to be established.
By using benzimidazole as an inexpensive and commercially available single-source for carbon and nitrogen, inventors produced different series of heteroatom-doped porous carbons through a single-step, solvent-free, reproducible and scalable process. A typical synthetic method consists of solid-state mixing of two commercially available substances, a nitrogen-rich monomer and a stabilizer/activator, followed by a subsequent heat treatment of powdery mixture. Formation of stable salt, char development and porosity generation take place at different stages of a single-step reaction. The materials produced show exceptionally high CO2 uptake at low pressures as well as high electrochemical capacitance, which makes them very promising for carbon dioxide capture and sequestration, and energy storage applications.