Phonon Dispersion Relation of Bulk Boron-Doped Graphitic Carbon

Abstract

Bulk turbostratic graphitic carbon of varying levels of disorder and chemical compositions has been synthesized by a direct synthesis method in the temperature range of 750−1100 °C, with a focus on boron incorporation within the graphitic lattice. The atomistic and electronic/vibrational structures were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, Auger electron spectroscopy, X-ray absorption spectroscopy, and Raman spectroscopy. The phonon dispersion relation of graphitic carbon was found to be uniquely sensitive to substitutional boron doping, which perturbs the phonon structure while leaving the lattice structure unchanged. The dispersion relation of the D peak measured by Raman spectroscopy can be used to uniquely identify bulk graphitic materials containing a large content of ordered trigonal planar g-BC 3 units, which are of high interest in applications ranging from hydrogen storage to lithium-ion batteries.

Hydrogen-Type Binding Sites in Carbonaceous Electrodes for Rapid Lithium Insertion

“…All four materials exhibit the usual features of the in-plane structure associated with graphite/graphene (the regime shown relates exclusively to in-plane phonons): the G and D modes, and their overtones and other defect-induced features. 26,27 The Raman spectrum of Cor800 exhibits a prominent G mode that is seemingly shifted to a higher frequency (1600 cm −1 ) than that of crystalline graphite (1564 cm −1 ), indicating the significant presence of the defect-induced D′ mode (typically found between 1700 and 1840 cm −1 ), not the actual change in frequency of G. This specifically signals the presence of electron-hole scattering sites in Cor800, which can also be seen in Super P and ZTC. While Cor800, Super P, and ZTC all exhibit a broad D mode, Cor800 exhibits some unique identifiable features on both shoulders of the D mode.…”

Carbon-Defect-Driven Boron Carbide for Dual-Modal NIR-II/Photoacoustic Imaging and Photothermal Therapy

“…X-ray photoelectron spectroscopy (XPS) analysis can additionally provide crucial evidence about the defects in B 4 C@C. The full spectrum of B 4 C@C (Figure S8) confirmed the B, C, and O atoms’ existence, respectively. Small traces of residual B 2 O 3 (peak entered at 193.7 eV) were detected for B 4 C (Figure D). As illustrated in Figure E, the peaks of B 1s centered at 188.8 and 187.8 eV can be associated with the B atoms in B–B , and B– sp 3 C bonds separately.…”

Biochar as a Renewable Substitute for Carbon Black in Lithium-Ion Battery Electrodes

“…The spectra were fitted and analyzed as described elsewhere. 23 X-ray diffraction (XRD) was performed using a Bruker D8 ADVANCE powder X-ray diffractometer with Cu Kα 1,2 radiation. XRD patterns were collected between 5 and 80°in 2θ using a step size of 0.02°per step.…”

“…Raman spectra were collected using a 50× long working distance objective, 1800 gr/mm grating, and by irradiation with a frequency-doubled Nd:YAG laser (532 nm) operated at 1–10 mW. The spectra were fitted and analyzed as described elsewhere . X-ray diffraction (XRD) was performed using a Bruker D8 ADVANCE powder X-ray diffractometer with Cu Kα 1,2 radiation.…”