Facile Self-Template Synthesis of a Nitrogen-Rich Nanoporous Carbon Wire and Its Application for Energy Storage Devices

Abstract

Heteroatom doping, pore engineering, and morphology design are efficient strategies to develop a high-performance electrode material for supercapacitors. In the periodic table of the elements, nitrogen is adjacent to carbon and their atomic radii are close to each other; therefore, the doping of nitrogen atoms can cause the lattice of the carbon material to be substantially distorted. In this study, a facile one-step self-template strategy for synthesizing a highly nitrogen-doped nanoporous carbon wire (denoted as HNPCW) of ∼100 nm diameter and ∼10 μm length is successfully developed. Depending on rational design and the control of reaction conditions, the highest surface area reaches 2149 m2 g–1, and the nitrogen content exceeds 16.8%. It is worth noting that the morphology of the materials varies as the contents of nitrogen change. The optimal HNPCW possesses a high specific capacitance of 587.8 F g–1 at 1 A g–1 in a three-electrode system, 118.9 F g–1 at 0.5 A g–1 in a two-electrode system, and excellent cycle stability (97.79% after 10 000 cycles at 5 A g–1). Even at a high specific power of 30.0 kW kg–1, the specific energy reaches 27.1 Wh kg–1, portraying great potential to be an ideal candidate for practical supercapacitors.

Carbon Nanofibers Based on Potassium Citrate/Polyacrylonitrile for Supercapacitors

“…In Figure S3 , the Ragone plots of C−1 show that the specific energy was calculated to be much better than the others at the same specific power. It had a good specific energy of 109 W·h·kg −1 at a specific power of 980 W·kg −1 , which was higher than the values of other carbon-based materials [ 20 , 36 , 37 ]. Furthermore, the specific energy of C−1 remained as high as 73.5 W·h·kg −1 even at a specific power of 9800 W·kg −1 .…”

Nitrogen and Sulfur Codoped Porous Carbon Directly Derived from Potassium Citrate and Thiourea for High-Performance Supercapacitors

“…For the samples of N,S-PC 1:4, 1:8, and 1:12, a new peak located at 400.5 eV (corresponding to N 1s) was observed, and two other peaks appearing at 164.5 and 228.2 eV were attributed to S 2p and S 2s, respectively, which proved that the N and S heteroatoms were successfully doped into the carbon framework . The high-resolution XPS C 1 s spectrum of the N,S-PC (1:12) (Figure S5) main peak, centered at approximately 284.60 eV, is attributed to C–C and/or CC, which can be fitted into four parts: CC (283.28 eV), C–C/C–O (284.68 eV), C–N (287.78 eV), and O–CO (290.53 eV) . The N 1 s spectrum (Figure e) is assigned to pyridinic N (N-6, 398.3 eV), pyrrolic N (N-5, 400.1 eV), and quaternary N (N-Q, 401.2 eV).…”

“…27 The high-resolution XPS C 1 s spectrum of the N,S-PC (1:12) (Figure S5) main peak, centered at approximately 284.60 eV, is attributed to C−C and/or C� C, which can be fitted into four parts: C�C (283.28 eV), C− C/C−O (284.68 eV), C−N (287.78 eV), and O−C�O (290.53 eV). 38 The N 1 s spectrum (Figure 2e) is assigned to pyridinic N (N-6, 398.3 eV), pyrrolic N (N-5, 400.1 eV), and quaternary N (N-Q, 401.2 eV). N-6 and N-5 can produce more defects, provide more active sites, and induce pseudocapacitance.…”

Rapid Synthesis of Oxygen-Enriched Porous Carbon through a Microwave Method and Its Application in Supercapacitors

“…The oxygen content in the samples decreased with increasing power owing to the gradual decrease in oxygen content with sufficient temperature at higher powers (10.51%, 8.06%, and 7.95% were the oxygen content of PC-325W-0.4, PC-425W-0.4, and PC-475W-0.4, respectively). However, the content of oxygen element in PC-275W-0.4 was 9.85%, which may be caused by an incomplete reaction where the low temperature of the reaction system inhibited the carbonization of the potassium citrate at lower power …”

“…42 To study the surface properties and pore structure, N 2 adsorption−desorption isotherms of PCs were measured at 77 K. Figure 3c shows the adsorption and desorption isotherms of PC-375W-1.0, PC-375W-0.75, PC-375W-0.5, PC-375W-0.4, and PC-375W-0.25, which conform to type I adsorption desorption isotherms. 43 It was clearly observed that the isotherms in the low pressure region and the high pressure region rise rapidly, which proved the existence of micropores and macropores. 44 The specific surface area, microporous surface area, pore volume, microporous volume, and average pore diameter of the PC samples are all listed in Table S3.…”