Graphitized hierarchical porous carbon nanospheres: simultaneous activation/graphitization and superior supercapacitance performance

Abstract

A novel graphitized porous carbon nanosphere (GPCNS) material was reported by a conveniently simultaneous activation and graphitization route, which was realized by heating resorcinol-formaldehyde (RF) resin nanospheres immersed with ZnCl 2 and FeCl 3 in an inert atmosphere. The high graphitization level was achieved through the catalytic graphitization by reduced metal Fe and the hierarchically micro/mesoporous structure was controllably produced by tuning the mass ratio of activating agent ZnCl 2 and carbon precursor. An optimal sample of GPCNS-2, which was prepared with a FeCl 3 /ZnCl 2 /RF mass ratio of 0.5:2:1, exhibiting a highly graphitized framework and uniform spherical morphology with an average diameter of ~500 nm, as well as well-interconnected micro/mesoporous structure and large surface area of 1664.8 m 2 g -1 . Behaved as an electrode material for supercapacitor application in 6 M KOH electrolyte, GPCNS-2 displayed excellently electrochemical performance with a high specific capacitance of 402.5 F g -1 at a current density of 1 A g -1 . More deeply, electrochemical impedance spectroscopy test demonstrated the low internal electrical resistance of GPCNS-2 that contributed a superior rate capability of above 75% retention ratio even at 50 A g -1 . Furthermore, GPCNS-2 electrode possessed outstanding cycling stability, and about 96% of its initial specific capacitance at 5 A g -1 was maintained after 5000 cycles.

One‐step Preparation of Carbon‐based Solid Acid Catalyst from Water Hyacinth Leaves for Esterification of Oleic Acid and Dehydration of Xylose

“…Further temperature increases (240 °C) result in C(002) peak sharpening and additional shifting to higher angle, although some broadening related to an amorphous or turbostratic carbon framework is still evident . Diffraction peaks due to C(101) and C(004) are more noticeable at this temperature, consistent with graphitization of the carbon framework …”

Synthesis of activated carbon nanospheres with hierarchical porous structure for high volumetric performance supercapacitors

“…Besides, the volumetric performance of sample CK21 also outperforms those of most previously reported advanced carbon-based 16 materials [13][14][15][16][40][41][42][43][44][45][46][47][48], although it is inferior to the most recently reported graphitized hierarchical porous carbon nanospheres with extremely high specific capacitance [49] (as shown in Table S1). The excellent capacitive performance of CK21 should be ascribed to several factors.…”

The Preparation of Porous Carbon Materials with High Pyridinic‐N Doping toward Efficient Oxygen Reduction Reactions

“…However, the ratio of I D / I G decreases to 0.9145 for WS350Z900@Fe, which might be ascribed to the fact that the reductive Fe 0 could accelerate the graphitization process during pyrolysis . In addition, ZnCl 2 would further promote the graphitization process, thereby facilitating the structural transformation from amorphous carbon to graphitic carbon . BET and Barrette–Joynere–Halenda (BJH) pore size distribution analyses were used to explore the surface area and pore structure of catalysts using N 2 adsorption–desorption experiments.…”