General Synthesis of Heteroatom‐Doped Hierarchical Carbon toward Excellent Electrochemical Energy Storage

Abstract

Heteroatom-doping is an effective approach to modify the microstructure of carbon-based materials toward enhanced electrochemical energy storage performance. Nevertheless, it is a great challenge to obtain a specific heteroatom-doped carbon material with hierarchical structure as a general doping strategy is missing. Herein, carbon materials doped with P, S and both of them are designed and precisely prepared through in-situ polymerization. Used as anode for sodium-ion batteries, the best performing material displays a high specific capacity of 368.6 mAh g À1 at a current density of 0.1 A g À1 after 100 cycles. A high capacity of 159.8 mAh g À1 is achieved at a large current density of 5 A g À1 . Impressively, this material also delivers robust storage performances for lithium. According to the firstprinciples method and detailed experimental data, the expanded interlayer distance and enhanced electronic conductivity of the microcrystalline region can be attributed to CÀS and PÀC bonds, while the high surface capacitance contribution can be assigned to surface CÀS species and highly exposed edges of the microcrystalline region. This work sheds light on a promising method for the exploitation of versatile heteroatom modified hierarchical carbon materials.

Construction of Functional Superhydrophobic Biochars as Hydrogen Transfer Catalysts for Dehydrogenation of N-Heterocycles

“…Finally, considering the possible effects of trace amounts of P species maintained in the DCNs, the P 2p spectrum of all samples are determined by X-ray photoelectron spectroscopy (Figure S7). For DC, DCN-750, and DCN-800 (Figure S7a–c), the P 2p spectrum can be deconvoluted into two peaks such as a P–C peak positioned at 133.6 eV and a P–O peak at 135.1 eV. − Obviously, the P–C/P–O ratio (peak area) is 0.95, 2.15, and 4.63, respectively, which indicate that the P–O groups on the surface of the catalytic materials may be converted to P–C groups with the increase of annealing temperature that is due to the reduction of carbon at high temperature. Similarly, with the further increase of annealing temperature, only P–C groups can be observed on the surface of other catalytic materials such as DCN-850, DCN-900, and DCN-950 (Figure S7d–f).…”

B, N‐codoped Cu–N/B–C Composite as an Efficient Electrocatalyst for Oxygen‐Reduction Reaction in Alkaline Media

“…The prepared composites were further analyzed by Raman spectroscopy. The Raman spectra of Cu–N/B–C‐900, Cu–N/B–C‐700, Cu–N/B–C‐800, Cu–N–C‐800, and N/B−C‐800 are shown in Figure B; the two peaks at 1338 and 1580 cm −1 correspond to the D‐band vibration mode of the sp 3 carbon atom in the defect structure and the G‐band vibration mode of the in‐plane sp 2 hybridized carbon, respectively . The I D /I G ratio for Cu–N/B–C‐700 (1.18), Cu–N/B–C‐800 (1.17), and Cu–N/B–C‐900 (1.16) decreased slightly as the temperature increased, suggesting that increasing the treating temperature reduces defects in carbon composites.…”

Marine polysaccharide-based electromagnetic absorbing/shielding materials: design principles, structure, and properties

“…[165][166][167] In the case of SA-derived carbon-based EMW absorbers with 3D porous skeletons and ferromagnetic metal nodes, the structural distortions and charge-density and electronic-structure modulations of the porous carbon skeletons can be induced by adjusting the kind and quantity of doped heteroatoms to introduce defects into the EMW absorbing system to promote dipole polarization and increase electron migration jumps to improve the electrical conductivity. 168,169 Pore engineering is another effective approach to enhance the EMW absorption performance of SA-derived carbon-based EMW absorbers. 170 The rational construction of interconnected networks of multiscale pores through heteroatom doping is conducive for improving the porosity, optimizing the interlayer of carbon, and increasing the specic surface area of SA-derived carbon-based EMW absorbers, further providing space and probability for multiple reections and scattering of EMW.…”