One‐Step Pyrolysis to Synthesize Non‐Graphitic Nitrogen‐Doped 2D Ultrathin Carbon Nanosheets and Their Application in Supercapacitors

Abstract

Non‐graphitic nitrogen plays a significant role in determining the electrochemical performance of carbon materials in the field of energy storage. However, the synthesis of carbon materials with a high level of non‐graphitic nitrogen doping is still a great challenge. In this paper, a facile one‐step pyrolysis approach was developed to synthesize 2D carbon nanosheets with a ultrahigh non‐graphitic nitrogen content. Through an ingenious design, g‐C3N4 and NH3, both generated during the pyrolysis process, play major roles in the generation of the non‐graphitic nitrogen‐doped carbon nanosheets. The intermediate g‐C3N4 acts as both a self‐sacrificial template and a nitrogen source, whereas NH3 offers a nitrogen‐enriched chemical atmosphere. Benefiting from the high pyridinic‐nitrogen content of the maternal g‐C3N4 and the reductive atmosphere of NH3, the as‐prepared carbon nanosheets exhibit a strikingly high non‐graphitic nitrogen content (up to 17.36 wt.%); also, thanks to the g‐C3N4 self‐sacrificial template, the as‐synthesized carbon nanosheets are 2D with an ultrathin thickness (3–4 nm) and a porous structure. These novel features make the as‐prepared carbon nanosheets an excellent supercapacitor electrode material in terms of superior specific capacitance (316.8 F g−1 at 1 A g−1), excellent cycling stability (without obvious capacitance loss after 10 000 cycles at 10 A g−1) and high energy density (up to 10.56 Wh kg−1 at a power density of 500 W kg−1). This work provides a new idea to prepare non‐graphitic nitrogen enriched carbon materials.

Poly(vinyl alcohol)‐assisted preparation of melamine resin‐derived thick plate‐like porous carbon for high‐performance all‐solid‐state supercapacitors

“…In contrast to most of the previously developed carbon‐based symmetrical SCs in aqueous solution electrolytes, our MTPC‐0.2‐based symmetrical SCs also exhibit remarkable E M (Figure 4(d)). 24,31,42–53 …”

2D Graphitic Carbon Nitride for Energy Conversion and Storage

“…Therefore, in order to reduce the content of graphite‐N in g‐C 3 N 4 , Li et al. [ 243 ] used melamine and glucosamine hydrochloride as precursors and adopted one‐step pyrolysis method (Figure 25d) to obtain ultrathin nongraphitic‐nitrogen‐enriched carbon nanosheets (NNCN‐800) with the content of nongraphitic‐nitrogen of 17.36 wt%. Moreover, the prepared NNCN‐800 showed excellent electrochemical performance, namely, a capacitance of 316.8 F g −1 at a current density of 1 A g −1 and 96% initial capacitance retention after 10 000 cycles (Figure 25e,f).…”

Boron and Nitrogen Co-Doped Porous Carbons Synthesized from Polybenzoxazines for High-Performance Supercapacitors

“…Nevertheless, traditional porous carbon-based supercapacitors show a small energy density from 5 to 10 Wh/kg, which seriously restricts their practical application in energy capture and storage [11][12][13][14]. Therefore, great efforts have been devoted to the synthesis of the high specific capacitance of new carbon materials to enhance their energy density [15][16][17].…”