Zeolitic imidazolate framework-derived nitrogen-doped porous carbons as high performance supercapacitor electrode materials

A series of nitrogen-doped porous carbons are prepared from nitrogen-containing zeolitic imidazolate framework (ZIF) and additional carbon sources (including melamin, urea, xylitol and sucrose) via co-carbonization at T = 950 °C. Results indicate that macromolecular carbon sources, say, sucrose, can effectively protect the nitrogen loss from ZIF backbone owing to the pre-melting and polymerization of the sucrose adsorbed on the ZIF surface in the carbonization process, which makes the corresponding ZIF-derived porous Carbon-ZS have high nitrogen content and excellent capacitive performance. The specific capacitance of Carbon-ZS in 6 M KOH solution reaches 285.8 F g−1 at a current density of 0.1 A g−1 owing to its relatively high nitrogen content and proper hierarchical pore structure. In particular, the capacitance of Carbon-ZS is higher than previously reported IRMOF-derived carbon, ZIF-67-derived carbon and ZIF-8/furfuryl alcohol co-derived carbon. Besides high capacitance, moreover, Carbon-ZS also shows excellent cycling stability and good electric conductivity as electrode materials for electric double-layer capacitors.