Coal tar pitch derived N-doped porous carbon nanosheets by the in-situ formed g-C3N4 as a template for supercapacitor electrodes-Huiqi Wang

N-doped porous carbon nanosheets (N-CNS) were prepared from coal tar pitch with the addition of urea and KOH activation. In the synthesis route, urea plays an important role in constructing the 2D sheet-likestructure, which serves as a nitrogen source, chemical blowing agent and the in-situ formation of g-C3N4self-degraded template. At a low activation temperature (600C), the as-prepared N-doped porouscarbon nanosheets possess high nitrogen content (7.06 at. %) and high speci?c surface area (1181 m2g-1),which offers remarkable capacitive performances due to the unique architecture and pseudocapacitancecontribution of the N doping. The N-CNS exhibits high capacitive performance (210 F g-1at 0.1 A g-1),and an excellent cycling stability. Additionally, the assembled symmetric supercapacitor displays an energy density of 7.15 Wh kg-1, and the capacitance retention remains 91.2% after 5000 cycles at 1 A g-1.The facile and low-cost route to massively prepare N-doped porous carbon nanosheets from coal tar pitch would be favorable to the applications of carbon materials for high performance supercapacitors.

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