Nitrogen-containing nanoporous carbon derived from ethylenediamine tetraacetate magnesium and the electrochemical enhancement by the addition of Mg(OH)2

Abstract

We demonstrate an efficient template carbonization method to produce nitrogen-containing nanoporous carbon materials at elevated temperatures, using ethylenediamine tetraacetate magnesium serving as carbon/nitrogen precursor and Mg(OH)2 as hard template. It reveals that the addition of Mg(OH)2 can greatly adjust the porous structures and thereby improve the electrochemical performance of the carbon materials. As a result, the carbon-1:3-800 sample prepared by heating the mixture of ethylenediamine tetraacetate magnesium and Mg(OH)2 (a mass ratio of 1:3) at 800 °C exhibits a large Brunauer–Emmett–Teller (BET) surface area of 766.8 m2 g−1, a high pore volume of 1.16 cm3 g−1, as well as a high nitrogen content of 9.48 %. Its specific capacitance can reach up to 367.5 F g−1 at a current density of 1 A g−1, and a high rate capability of 47.3 % also appears at a high current density of 40 A g−1, when electrochemical measurement is carried out in a three-electrode system, using 6 mol L−1 KOH aqueous solution as electrolyte. It should be pointed out that the ethylenediamine tetraacetate magnesium commonly produced in the analysis process is always discarded as solid waste. Therefore, the present template carbonization method has opened a simple but efficient avenue to convert this kind of solid waste into nanoporous carbon materials, acting as superior supercapacitor electrode materials.