Confident methods for the evaluation of the hydrogen content in nanoporous carbon microfibers

Abstract

Nanoporous carbon microfibers were grown by chemical vapor deposition in the vapor-liquid solid mode using different fluid hydrocarbons as precursors in different proportions. The as-grown samples were further treated in argon and hydrogen atmospheres at different pressure conditions and annealed at several temperatures in order to deduce the best conditions for the incorporation and re-incorporation of hydrogen into the microfibers through the nanopores. Since there are some discrepancies in the results on the hydrogen content obtained under vacuum conditions, in this work, we have measured the hydrogen content in the microfibers using several analytical methods in ambient conditions: surface tension, mass density, and Raman measurements. A discussion on the validity of the results obtained through the correlation between them is the purpose of the present work.

Electrical conductivity properties of expanded graphite-polycarbonatediol polyurethane composites

“…In order to quantify the interaction degree between PUPH and EG the spectra were fitted to Lorentz curves to determine the areas of the corresponding bands, I D and I G . The ratio of the area of the D‐band to that of the G‐band ( I D / I G ) can be related to the order in carbonaceous materials . The I D / I G ratio was calculated for EG and PUPH/50EG because at compositions below 50 wt% EG the D‐band is not well resolved.…”

“…The ratio of the area of the D-band to that of the G-band (I D /I G ) can be related to the order in carbonaceous materials. 38 The I D /I G ratio was calculated for EG and PUPH/50EG because at compositions below 50 wt% EG the D-band is not well resolved. The ratio I D /I G in the sample with 50 wt% EG is 0.07, lower than that corresponding to pristine EG (0.16).…”

Review—Towards the Next Generation of Thermoelectric Materials: Tailoring Electronic and Phononic Properties of Nanomaterials

“…[11][12][13] For instance, in the case of polyaniline (PANI), initially a thorough analysis of the synthetic factors that affect its thermoelectric properties was performed. Therefore, the polymerization kinetics, structural characterization, and thermoelectric properties were studied.…”

Effects of Gamma Irradiation on the Kinetics of the Adsorption and Desorption of Hydrogen in Carbon Microfibres

“…Besides, we have used Raman spectroscopy to determine the crystallite size, L a [27] and the hydrogen content [28], as it is shown in Figure 8.…”

“…In previous works, the ratio of the intensities of the Raman bands D and G has been proven to be an appropriate tool for the evaluation of the crystallite size, L a [27]. Similarly, the ratio between the areas of the peaks D and G are a valid parameter to evaluate the hydrogen content [28].…”