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After a brief overview of the discovery and the Raman study of new forms of carbons (intercalated graphite, carbon fiber, fullerenes, carbon nanotubes), the invaluable contribution of late Professor M. Dresselhaus is noted, and the 10 reviews and 9 contributions collected to present a picture of the current Raman investigations of graphene and related 2D materials (such as black phosphorus, MoS2) are introduced. Methods for numbering the graphene layers, the effects of external perturbations (temperature, pressure, doping, and magnetic field) on the phonons of graphene, characterization of the chemical and structural properties of graphene at the nanoscale level by tip‐enhanced Raman spectroscopy, surface enhanced Raman spectroscopy and hyperspectral imaging, and applications combining graphene and Raman spectroscopy are addressed. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Few-layer graphene (FLG) samples prepared by two methods (chemical vapor deposition (CVD) followed by transfer onto SiO2/Si substrate and mechanical exfoliation) are characterized by combined optical contrast and micro-Raman mapping experiments. We examine the behavior of the integrated intensity ratio of the 2D and G bands ( A2D/ AG) and of the 2D band width ( Γ2D) as a function of the number of layers ( N). For our mechanically exfoliated FLG, A2D/ AG decreases and Γ2D increases with N as expected for commensurately stacked FLG. For CVD FLG, both similar and opposite behaviors are observed and are ascribed to different stacking orders. For small (respectively, large) relative rotation angle between consecutive layers ( θ), the values of the A2D/ AG ratio is smaller (respectively, larger) and the 2D band is broader (respectively, narrower) than for single-layer graphene. Moreover, the A2D/ AG ratio decreases (respectively, increases) and, conversely, Γ2D increases (respectively, decreases) as a function of N for small (respectively, large) θ. An intermediate behavior has also been found and is interpreted as the presence of both small and large θ within the studied area. These results confirm that neither A2D/ AG nor Γ2D are definitive criteria to identify single-layer graphene, or to count N in FLG. [ABSTRACT FROM AUTHOR]

In this article, we report the synthesis of ultra-long carbon nanotubes (CNTs) by thermal chemical vapour deposition method. Ultra-long, individual and aligned CNTs were directly grown on a flat silicon substrate. The orientation of the nanotubes was found parallel to the gas flow direction. The ultra-long CNTs were grown with different transition metallic salts, such as nickel chloride, iron (III) chloride, cobalt acetate and ruthenium acetate, as the catalysts. The influence of the growth conditions, such as growth temperature, reactive gas flow on the length and alignment of the CNTs was studied in detail. By using different catalysts, ultra-long single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) were successfully grown. These ultra-long CNTs were transferred to other substrates by two methods. (1) The first method is to use polydimethylsiloxane as a stamp. (2) The second method is to use KOH as an etching agent. The diameter and length of the CNTs were characterised by transmission electron microscope, scanning electron microscope, atomic force microscope and Raman spectroscopy. The results indicate that the length of the CNTs can reach up to 4 mm. The diameter of the SWCNTs is in the range of 0.7-2.1 nm and the diameter of the MWCNTs is approximately 150 nm. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a versatile catalyst-assisted chemical vapor deposition (CVD) technique for the synthesis of single-walled carbon nanotubes (SWNTs) from discrete nickel nanoparticles (average diameter of 4.7±1.5 nm). Atomic force microscopy (AFM), transmission electron microscopy (TEM) and electron diffraction are used to characterize these as-grown nanotubes. On a particular sample we found that the SWNTs have an average chiral angle of 25.3°. This result shows that a control of the chiral angle of SWNT with large diameters (mean diameter=1.75 nm) and with a relatively broad diameter distribution (standard deviation=0.5 nm) is achievable to a certain extent. [Copyright &y& Elsevier]

Abstract: We have developed a versatile catalyst-assisted chemical vapor deposition (CVD) technique for the synthesis of single-walled carbon nanotubes (SWNTs) from discrete nickel nanoparticles (average diameter of 4.7±1.4 nm). Atomic force microscopy (AFM), transmission electron microscopy (TEM) and micro-Raman spectroscopy are used to characterize these as-grown nanotubes. Using a conventional set-up, we are able to produce isolated SWNTs with a narrow diameter distribution (1.5±0.5 nm). The advantages of such a versatile CVD method for the study of physical properties at the single nanotube level are illustrated by means of two prospective studies on vibrational and electrostatic properties of SWNTs. [Copyright &y& Elsevier]

Consider advances are being made to develop new technologies capable of fast in-situ tracing of agricultural toxins. In this work, we reported a simple carbaryl sensor with very high sensitivity using graphene interdigitated ion selective field effect transistor (ISFET). The graphene films were first prepared on polycrystalline copper foil by a low-pressure chemical vapor deposition method, and then transferred onto the interdigitated electrodes of ISFETs by a chemical etching technique. The biorecognition is based on the enzymatic inhibition of carbaryl towards urease. As expected, the weaker enzymatic activity of urease in addition of carbaryl would result in the weaker current response. It was demonstrated that the interdigitated ISFET sensor could achieve high sensitivity to detect carbaryl as low as 10 −8  μg mL −1 and the current response of the device showed a good linearity against the logarithm of carbaryl concentration C carbaryl with a regression equation ΔI ds  = −0.4 − 0.6 logC carbaryl (mA) (R 2  = 0.99) in the concentration range from 2.58 × 10 −7 to 2.58 × 10 −2  μg mL −1 . In conlusion, such convenient graphene-based ISFET configuration could be advantageously extended for on-line screening of other pesticide and herbicide agents. [ABSTRACT FROM AUTHOR]