Graphitic nitrogen-doped carbon film/nanoparticle composite, in which the films were wrapped and separated by the nanoparticles, was prepared through a simple co-calcination route. Due to its unique porous structure and improved nitrogen content, the as-prepared electrode material could exhibit high specific capacitances of 317.5 F g− 1 at 0.5 A g− 1 and 200.0 F g− 1 at 20 A g− 1, and stable cycling behavior with no capacitance decline after 10,000 cycles in three-electrode system. When assembled in two-electrode capacitor, its specific capacitance could be well kept at 265.5 F g− 1 at 0.5 A g− 1, and thus the supercapacitor with a high energy density of 9.22 Wh kg− 1 was obtained. The superior energy storage properties of the as-prepared material indicate its promising application as high-performance carbon-based electrode for supercapacitors.

Graphitic carbon nitride film deposited with nitrogen-doped carbon nanoparticles as electrode for high-performance supercapacitors
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 The preparation of HPNC-x
        2.3 Characterization
        2.4 Electrochemical measurements
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Jun Zhu( Jiangsu Key Laboratory of Traffic and Transportation Security, Faculty of Transportion Engineering, Huaiyin Institute of Technology, Huaian 223003, People’s Republic of China)
• Qiang Ma(Jiangsu Food & Pharmaceutical Science College, Huaian 223003, People’s Republic of China)
• Lirong Kong(School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, People’s Republic of China)
• Jianguo Dai(Jiangsu Key Laboratory of Traffic and Transportation Security, Faculty of Transportion Engineering, Huaiyin Institute of Technology, Huaian 223003, People’s Republic of China)
• Keqiang Xu(Jiangsu Key Laboratory of Traffic and Transportation Security, Faculty of Transportion Engineering, Huaiyin Institute of Technology, Huaian 223003, People’s Republic of China)
• Quanrun Chen(Hua Neng Huaiyin Power Plant, Huaian 223001, People’s Republic of China)
• Zhiguo Zhao(Jiangsu Key Laboratory of Traffic and Transportation Security, Faculty of Transportion Engineering, Huaiyin Institute of Technology, Huaian 223003, People’s Republic of China)