Nitrogen doped heat treated and activated hydrothermal carbon: NEXAFS examination of the carbon surface at different temperatures

X-ray Raman scattering for bulk chemical and structural insight into green carbon

“…46 In a recent NEXAFS study of model-compound-derived hydrothermal carbon by Latham et al, the transition at 286.6 eV was assigned as the 1s-p* furan transition for the a-carbon (C-O) atom. 7,8 This assignment agrees with previous 13 C-NMR studies by Falco et al, who suggest several furan-furyl-type structural sub-units which are congruous with the accepted hydrothermal carbon model. 13,47 Recent advances in density functional theory (DFT) codes now allow for the ab initio calculation of XRS spectra for simple molecular structures.…”

“…Pyrolysis and hydrothermal carbons are amorphous, high molecular weight carbonaceous materials with complex spectroscopic signatures. In order to study changes in carbon chemistry in hydrothermal and pyrolysis carbons, current literature relies on spectroscopy obtained ex situ by Fourier-transform infrared spectroscopy (FT-IR), 5 X-ray photoelectron spectroscopy (XPS), 6 soft X-ray absorption spectroscopy (NEXAFS) 7,8 or solid-state Carbon NMR ( 13 C-NMR). 9 Increasingly, however, FT-IR, 13 C-NMR, XPS or NEXAFS are not sufficient to gain well-resolved, bulk, local structural information due to at least one of two limitations: surface bias and low sensitivity.…”

General Method for Synthesis Transition‐Metal Phosphide/Nitrogen and Phosphide Doped Carbon Materials with Yolk‐Shell Structure for Oxygen Reduction Reaction

“…The normalized N K‐edge XANES spectra of Fe 2 P/NPC, Co 2 P/NPC and Ni 2 P/NPC in Figure B reveal the different functional groups of nitrogen doped into the carbon materials. Three peaks can be observed at 399.8 eV, 402.3 eV, and 407.9 eV arising from the π* transition of C=N for pyridinc‐N, π* transition of C=N belonging to pyrrolic‐N and the transition σ* states of C−N bonds, respectively . The normalized P K‐edge XANES spectra of NPC, Fe 2 P/NPC, Co 2 P/NPC and Ni 2 P/NPC all show strong peak at 2.152 keV mainly formed by P atoms and C atoms suggesting phosphorus doped in carbon .…”

Single‐Step Synthesis of Mesoporous Carbon Nitride/Molybdenum Sulfide Nanohybrids for High‐Performance Sodium‐Ion Batteries

“…Absorption peaks at 398.5, 399.6 and 401.2 eV are responsible for excitations to π* pyridinic N , π* N=CÀ N and π* tertiary N , respectively. [27,30,33,34] A characteristic peak at 397.1 eV of the Ndoped MoS 2 is not observed in the N K-edge NEXAFS spectra of all present samples, which excludes the possibility of N-doping into the MoS 2 . [35] While the CN/MoS 2 -500 shows a dominant feature of pyridinic N, characteristics of N=CÀ N and tertiary N bonds become distinct for the CN/MoS 2 -800.…”