Single-Step Synthesis of N-Doped Three-Dimensional Graphitic Foams for High-Performance Supercapacitors

Abstract

We present a facile yet efficient single-step pyrolysis method to prepare bulk-scale high-performance Ndoped 3D-graphitic foams with various length-scale pores. The iron precursors act as catalysts for the conversion of organic substances to a graphitic structure while simultaneously providing a rigid template that prevents the aggregation of organic components, and soluble polymers act as a carbon source for the formation of N-doped multilayer graphene under high-temperature and inert conditions. The 3Dgraphitic foams possess highly interconnected networks composed of micro-, meso-, and macropores with a specific surface area of up to 1509 m 2 g −1 and a high conductivity of 10 S m −1 . The resulting 3D-graphitic foams exhibited specific capacitance values of 330 and 242 F g −1 with outstanding cycling stability (a 23% loss after 100 000 cycles for a symmetric cell) in a three-electrode system and in a symmetric cell, respectively, when used as active materials in a supercapacitor. This study suggests the great potential of bulk-scale fabricated N-doped 3D-graphitic foams with a large surface area and excellent conductivity, as well as controlled porosity, for applications in various fields.

Hierarchically Structured Multidimensional Carbon Composite Anchored to a Polymer Mat for a Superflexible Supercapacitor

“…3D-Gn was synthesized by calcining a polymeric carbon precursor in a hard template in the presence of a catalyst for graphitization (Figure S17). The detailed procedure for the 3D-Gn synthesis was described in our previous reports. − A 9 g amount of fumed silica (SiO 2 as the hard template; 5 nm in size; Sigma-Aldrich) was dispersed in 45 mL of aqueous solution containing 5 g of PVP (as the carbon precursor) and 17.5 g of FeCl 3 ·6H 2 O (as the catalyst precursor). The mixture was vacuum-dried at room temperature (step 1) and then pyrolyzed at 900 °C for 30 min in a continuous flow of H 2 /Ar at 100/1000 cm 3 min –1 (step 2).…”

“…The two-dimensionality of graphene and graphene-like materials (2D-Gn’s) is the benefit from the flexibility standpoint because the π–π stacking of 2D-Gn’s supports physical integrity against external bending forces . From the capacitance standpoint, however, the 2D-Gn stacks possibly reduce the surface area available for electric double layer formation, decreasing capacitance. − To overcome the demerits of 2D-Gn assembly, three-dimensional graphene networks (3D-Gn’s) were proposed. − Highly developed porous networks of 3D-Gn’s allowed ions to have easy access to the whole surface through porous channels. ,− …”

Homogeneous coating of carbon nanotubes with tailored N-doped carbon layers for improved electrochemical energy storage

“…20,21 Nevertheless, a controllable N-doping level and optimized morphology are still essential for improving the electrochemical performance. 22 In this work, N-doped carbon/CNT hybrids (N-CNTs) were successfully synthesized via the carbonization of polyimide/ CNT precursors (PI@CNTs), which were prefabricated by an in situ hydrothermal polymerization approach in the presence of CNTs. The as-prepared N-CNTs exhibited a core-shell structure with a controllable N-content up to 3.2 wt%.…”

“… 20,21 Nevertheless, a controllable N-doping level and optimized morphology are still essential for improving the electrochemical performance. 22 …”

Facile Synthesis of Porous‐Carbon Nanoarchitectures as Advanced and Durable Electrodes for Supercapacitors

“…Figure d collects the typical Raman spectra of the KZCC, ZCC, and CC samples. Two characteristic peaks are identified for three samples: D‐band at 1314 cm −1 , and G‐band at 1593 cm −1 . The D‐band is originated from hybridized vibrational mode associated with the edges, disorder and defects of carbon materials, while the G‐band is corresponding to graphic structure, the tangential oscillation and vibration of the sp 2 carbon atoms .…”