Tuning Confined Nanospace for Preparation of N‐doped Hollow Carbon Spheres for High Performance Supercapacitors

Abstract

The structural parameters and surface functionalities of hollow carbon spheres are critical for their electrochemical performance. Herein, preparation of N‐doped‐hollow carbon spheres (N‐HCS) with tunable structural parameters and surface properties is reported by using a confined pyrolysis strategy. Polystyrene/polyaniline (PSPAN) was pyrolyzed in a silica shell, which provided a confined nanospace. PSPAN functioned as both the core and a source of carbon and nitrogen. The surface properties and structural parameters of the obtained N‐HCS could be optimized by regulating the pore size of the silica shell. The silica shell coating also prevented agglomeration of the N‐HCS, leading to a regular and well‐distributed spherical morphology. The N‐HCS synthesized in relatively porous conditions had thinner shell, larger mesopore size, higher surface area, and higher nitrogen content and showed excellent electrochemical performance as a supercapacitor with a specific capacitance of 436.5 F g−1 at 0.5 A g−1.

Heteroatom‐Doped and Oxygen‐Functionalized Nanocarbons for High‐Performance Supercapacitors

“…[145] N-doped hollow carbon spheres with open pore structure showed good performance as a supercapacitor electrode due to the high surface area, larger mesoporous channels, suitable pore size distribution, and thin outer shell that ensures the accessibility and pathways for electrolyte ions, as compared to N-doped hollow carbon spheres with the closed and semiclosed pore structure. [146] Hence, tuning the porosity of doped nanocarbons along with controlled N-content and its configuration is an effective means to yield high-performance supercapacitor electrode materials. Capacitative performance of N-doped nanocarbons.…”

Incorporation of copper nanoparticles into the nitrogen‐doped carbon derived from nitrile functionalized ionic liquid as the non‐precious heterogeneous catalytic system toward nitro compounds reduction reaction, a first principle calculation

“…Their secure synthesis method, low‐cost precursor, regulated morphological structure, specific surface area, and acceptable stability towards high thermal and chemical conditions make them a good choice for many purposes 8‐12 . Among the miscellaneous types of N‐doped carbon materials, Covalent Triazine Frameworks (CTFs) have been introduced as one of the most distinguished mesoporous materials due to their great supply of nitrogen sites and extreme thermal and chemical resistance, all of which are related to the covalent bonding nature of triazine unites in their structure; in other words, the aromatic character of the C═N bond in the construction of the CTFs caused the excellent stability toward harsh conditions 13‐17 . These materials were synthesized by direct carbonization of nitrogen‐containing carbon precursors (such as melamine and urea) or post‐treatment of carbonous substrates with nitric acid, ammonia, amines, etc.…”

“…[8][9][10][11][12] Among the miscellaneous types of N-doped carbon materials, Covalent Triazine Frameworks (CTFs) have been introduced as one of the most distinguished mesoporous materials due to their great supply of nitrogen sites and extreme thermal and chemical resistance, all of which are related to the covalent bonding nature of triazine unites in their structure; in other words, the aromatic character of the C═N bond in the construction of the CTFs caused the excellent stability toward harsh conditions. [13][14][15][16][17] These materials were synthesized by direct carbonization of nitrogen-containing carbon precursors (such as melamine and urea) or post-treatment of carbonous substrates with nitric acid, ammonia, amines, etc. in the past; [18][19][20][21] nowadays, due to the growing demands for these materials in various applications, the design of various nitrogen-containing substrates has been improved by using different methods and introducing new precursors.…”

Construction of Dual‐Mesoporous Carbon Fibers Via Coassembly for Supercapacitors

“…For the MCF precursor, the degradation of CTAB is between 200 and 300 °C, followed by the decomposition of PF resin into carbon. In contrast, the TGA curve of DMCF precursor shows two weightlessness trends, which are attributed to CTAB and F127 with weight loss in the range of 200–300 and 300–400 °C, [2b,16] indicating that F127 has successfully participated in the assembly.…”