Direct chemical synthesis of nitrogen-doped graphynes with high supercapacitance via a cross-coupling copolymerization strategy

Development of graphyne-type carbon materials, which are constructed by different combination of sp2 and sp hybridized carbon atoms, has been a thriving research hotspot in material science, due to their promising application in a range of energy and environmental fields. Herein, nitrogen-doped graphyne materials (NGY-1 and NGY-2) were directly synthesized by Sonogashira-Hagihara cross-coupling reaction, using hydrogen-deficient multi-acetylene and polyhalide compounds as the comonomers. NGY-1 and NGY-2 possess two-dimensional porous structure, high nitrogen content and homogenous nitrogen distribution. After heat-treatment at the temperature of 800 °C, the obtained materials NGY-1–800 and NGY-2–800 demonstrate high supercapacitive energy storage performances with specific capacitances up to 312 F g−1 at 0.1 A g−1 and excellent cycling properties. Compared with NGY-1–800, NGY-2–800 obtained from the pyrazine-containing precursor, exhibits a better rate capability thanks to higher content of graphitic nitrogen doping. The copolymerization strategy developed here can potentially provide a rational design principle and open a new gateway for the construction of novel graphyne-type carbon materials for energy storage applications.