X-Ray Emission Spectra of Graphene Nanosheets

Abstract

Investigations of the electronic structure of graphene nanosheets synthesized by the reduction of oxidized graphene nanosheets were carried out using ultra-soft X-ray emission spectroscopy (USXES). Oxidized graphene nanosheets were produced from carbon nanofiber starting material using a modified Hummers method. X-ray diffraction, and scanning and transmission electron microscopy investigations were used in addition to USXES to study the electronic structure evolution from carbon nanofibers to graphene nanosheets. The effect of the degree of corrugation of the graphene nanosheets on the fine structure of the CK(alpha)-emission bands was revealed by USXES. It was found that corrugation of the graphene nanosheets is caused by overlapping of the pi-orbitals and formation of mixed (sigma + pi)-states.

Silk Fibroin-Based Piezoelectric Sensor with Carbon Nanofibers for Wearable Health Monitoring Applications

“…The 2θ degree equal to the 19.2˚ diffraction peak is attributed to the Silk I crystal structure, and the 2θ degree equal to the 23.2° diffraction peak corresponds to the Silk II structure associated with crystalline beta-sheet [ 32 ]. The 2θ degree equal to the 26.5° diffraction peak corresponds to the CNFs, and it resembles the 002 lattice plane interlayer arrangement of carbon [ 33 ]. The crystallinities of the samples range from 46.4% to 60.1%.…”

2D Graphene Structures for Safe Explosion Works Produced by Self-Propagation High Temperatures Synthesis

“…Summarizing the data of complementary electron microscopy methods and spectrometric analysis methods, namely: the presence of a wide diffuse maximum around the value of 2θ = 26.5° in the diffraction pattern and the presence of three characteristic lines (peaks) in the Raman scattering spectrum of carbonized lignin samples, as well as data for the true density allows us to compare the obtained carbonized samples with samples few-layer graphene described in literature [37][38][39]. Taking into account of the method, we denote it as FLGsvs.…”

Safe Explosion Works Promoted by 2D Graphene Structures Produced under the Condition of Self-Propagation High-Temperature Synthesis

“…Summarizing the data of complementary electron microscopy methods and spectrometric analysis methods, namely the presence of a wide diffuse maximum around the value of 2θ = 26.5° in the diffraction pattern and the presence of three characteristic lines (peaks) in the Raman scattering spectrum of carbonized lignin samples, as well as the data for the true density allowed us to compare the obtained carbonized samples with the fewlayer graphene samples described in literature [25][26][27]. Taking into account this method, we denoted it as FLGsvs.…”

“…The advantage of this composition over traditional primary Ems is the absence of heavy and toxic metals in the composition. Previously, similar pyrotechnic compositions showed pretty high sensitivity to various electrophysical pulses (such as a high-current electron beam of nanosecond duration, a high-voltage discharge, and an electrical explosion of a semiconductor Summarizing the data of complementary electron microscopy methods and spectrometric analysis methods, namely the presence of a wide diffuse maximum around the value of 2θ = 26.5 • in the diffraction pattern and the presence of three characteristic lines (peaks) in the Raman scattering spectrum of carbonized lignin samples, as well as the data for the true density allowed us to compare the obtained carbonized samples with the few-layer graphene samples described in literature [25][26][27]. Taking into account this method, we denoted it as FLGsvs.…”