Optical properties of graphite oxide and reduced graphite oxide

Abstract

We studied the optical properties of a graphite oxide and a reduced graphite oxide by using the optical spectroscopic technique. The graphite oxide does not show a finite dc conductivity and has several characteristic absorption modes in the mid-infrared region, caused by an epoxide functional group and hydroxyl and carboxyl moieties in the mid-infrared range. The reduced graphite oxide shows a Drude-like response in the far-infrared region and the estimated dc conductivity and electric mobility are around 200 −1 cm −1 and ∼100 cm 2 V −1 s −1 , respectively. We found that the optical conductivity cannot be fitted with a simple Drude model, which indicates that the charge carriers are correlated. We applied an extended Drude model and obtained the optical scattering rate and the optical effective mass. We found that the optical effective mass can carry information of both the enhanced mass by correlation and the electronic band structure.

Study of the absorption coefficient of graphene-polymer composites

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Figure 4 ( a ) Normalized transmittance as a function of graphene loading together with Beer-Lambert model (solid lines) plotted for three ranges. ( b ) Calculated absorption coefficient in respect to the wavelength (and frequency) in three spectral ranges compared with literature data for similar materials 51 , 59 – 62 .

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“…The values of absorption coefficient in respect to the wavelength are shown in Fig. 4(b) as filled squares and compared to other similar materials 51 , 59 – 62 . In the first and second range the has similar values and can be averaged to a value of and , respectively.…”

Facile and size-controllable preparation of graphene oxide nanosheets using high shear method and ultrasonic method

“…GO has recently attracted substantial interest as a possible intermediate for the preparation of graphene [11][12][13] and metal oxide/graphene nanocomposites [14][15][16]. It also has been used to prepare a strong paper-like material owing mainly to their interesting electrical, thermal, mechanical and optical properties [1,8,10,[17][18][19][20][21][22]. The small area of GO sheets results in high inter-sheet contact resistance in the films due to a large amount of intersheet junctions [10,23,24].…”

Dynamic surface properties of PEG-coated CuS nanoparticles alter their interaction with cells as revealed by surface-enhanced infrared spectroscopy

“…The optical permittivity parameters of Au and rGO used in simulation were extracted from the data of Palik and Hwang. 67,68 Plasmon nano-imaging Scattering-type scanning near-eld optical microscopy (s-SNOM, Molecular Vista) used for this work was based on an AFM probe (a gold coated Si cantilever, 70 nm tapping amplitude and 270 kHz resonance frequency), which was illuminated by focused infrared light from a pulsed quantum cascade laser (QCL, Block Engineering). The plasmon nano-imaging of the sample could be obtained simultaneously via mapping the topography and the near-eld scattered intensity detected using a liquid-nitrogen-cooled MCT detector.…”