Heteroatom-doped porous carbons for clean energy applications and methods for their synthesis
Methods for a facile, template free and one-step synthesis of nanoporous carbons by using a heterocyclic aromatic organic compound as a single source precursor of both carbon and nitrogen are described. The heterocyclic aromatic organic compound contains nitrogen in pyrrolic and/or pyridinic positions and is chemically activated with NaOH, KOH or ZnCl 2 at high temperatures in a solid state mixture as a synthesis protocol to promote fine micropores during carbonization. Nanoporous carbons synthesized by these methods that have superior gas sorption/storage and energy storage properties are also described. The nanoporous carbons are useful as carbon sequestration agents and supercapacitors.
1. A method of synthesis of a nitrogen-doped porous carbon, comprising:
preparing a solventless or solid-state mixture of (i) benzimidazole and (ii) zinc chloride (ZnCl 2 ), sodium hydroxide (NaOH) and/or potassium hydroxide (KOH);
subjecting the solventless or solid-state mixture to heat at a temperature sufficient to induce pyrolysis of the solventless or solid-state mixture to form a nitrogen-doped porous carbon.
2. The method of claim 1 , wherein the solventless or solid-state mixture does not comprise a metal organic framework compound.
3. The method of claim 1 , wherein the solventless or solid-state mixture comprises a weight ratio of ZnCl 2 to benzimidazole or KOH to benzimidazole or NaOH to benzimidazole in the range of about 0.5-4.
4. The method of claim 1 , wherein the solventless or solid-state mixture comprises a weight ratio of ZnCl 2 to benzimidazole or KOH to benzimidazole or NaOH to benzimidazole in the range of about 2:1.
5. The method of claim 1 , wherein the temperature ranges from 700° C. to 1000° C.
6. The method of claim 1 , wherein the nitrogen-doped porous carbon has a surface area in the range of about 525-855 m 2 g −1 and a total pore volume in the range of about 0.21-0.33 cm 3 g −1 .
7. The method of claim 1 , wherein the nitrogen-doped porous carbon has a surface area in the range of about 830-3320 m 2 g −1 and a total pore volume in the range of about 0.33-1.89 cm 3 g −1 .
8. The method of claim 1 , wherein the nitrogen-doped porous carbon has a surface area of about 350 m 2 /g and a total pore volume of about 0.15 cm 3 /g.