Highly Doped Carbon Nanobelts with Ultrahigh Nitrogen Content as High‐Performance Supercapacitor Materials

Abstract

Nitrogen-doped and nitrogen and oxygen codoped carbon nanobelts (CNBs) (denoted as N-CNBs and N-O-CNBs, respectively) are respectively obtained by pyrolyzing the self-aligned polypyrrole (PPy) NBs and Se@poly(2-methoxy-5-nitroaniline) core@shell nanowires. Particularly, the uniform size, unique nanostructure, and well-defined edges of the PPy NBs result in the uniform size of the doped CNBs with an extraordinarily high N doping level (≈16 at%), especially the very large concentrations of the redox active pyridinic (9 at%) and pyrrolic N (3.5 at%) species. Furthermore, the precursors in highly self-aligned, dense arrays give rise to a very high packing density for the N-CNBs and N-O-CNBs. These incomparable features provide not only appropriate pathways for the introduction of pseudocapacitance via rapid Faradaic reactions and enhancement of volumetric capacitance but also structural design and synthesis approach to new types of nanostructured carbon. Notably, the N-CNBs obtained at the pyrolysis temperature of 800 °C (N-CNB8) in symmetric electrochemical cells deliver a specific capacitance of 458 F g and ultrahigh volumetric capacitance of 645 F cm in aqueous solution, which are among the best performance ever reported for carbon-based supercapacitive materials.

Nitrogen-Doped TiO2–C Composite Nanofibers with High-Capacity and Long-Cycle Life as Anode Materials for Sodium-Ion Batteries

“…In the N 1 s spectrum of the TiO 2 /N–C NFs (Fig. 5 d), four forms of nitrogen in carbon can be observed: pyridinic N (N-6) at 398.47 eV, pyrrolic/pyridone N (N-5) at 400.05 eV, quaternary N (N-Q) at 401.01 eV, and pyridine-N-oxide at 403.19 eV [ 59 , 60 ]. These different types of nitrogen are shown schematically in Fig.…”

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

“…For example, even with a laborious procedure, Tan et al fabricated a 3D porous carbon with a nitrogen‐doped level of only 7.5 %–7.8 % . Su and coauthors synthesized carbon nanobelts (CNBs) with a N‐doping level of 16 at.% through a complex series treatments, which includes hydrothermal, etching, and pyrolysis processes . Actually, it is more complicated than expected when it comes to electrode materials for supercapacitors.…”

“…[12] Su and coauthors synthesized carbon nanobelts (CNBs) with a N-doping level of 16 at.% through a complex series treatments, which includes hydrothermal, etching, and pyrolysis processes. [13] Actually, it is more complicated than expected when it comes to electrode materials for supercapacitors. Firstly, nitrogen-doped carbon materials usually contain three different configurations of nitrogen species, i. e., pyridinic-, pyrrolic-and graphitic-nitrogen (pyridinic-and pyrrolic-nitrogen are also called non-graphiticnitrogen), [14] only the former two are preferred because they could offer pseudocapacitance via proton incorporation.…”

In Situ Encapsulation of Iron Complex Nanoparticles into Biomass‐Derived Heteroatom‐Enriched Carbon Nanotubes for High‐Performance Supercapacitors

“…Nanostructured carbon materials such as carbon nanotubes and graphene provide high specific surface area offering opportunities to store more charges, but it is still not enough to realize significant improvement in energy density of supercapacitors based on carbon materials . An alternative strategy for further enhancing the specific capacitance of nanostructured carbon materials has been developed through incorporating heteroatoms into the carbon framework . The incorporated heteroatoms could provide extra pseudocapacitive contributions from the fast faradic reactions between the heteroatom containing functional groups and the electrolyte ions, and sometimes the heteroatoms doping could optimize the surface wettability and the electronic conductivity of carbon materials, thus both benefiting to the improvement in the capacitive performance of carbon materials .…”