What is 2D peak in graphene?

2D peak is secondary D peak. It has pronouned, the largest intensity in single layer graphene, but it broadens (into four peaks) and reduces in intensity in multi-layer graphene. Normally, there is not much difference as you can observe from graphite if it’s more than five layers.

What is 2D band in Raman spectra?

Combined with the G-band, this spectrum is a Raman signature of graphitic sp2 materials and is called 2D(G*)-band. 2D-band is a second-order two-phonon process and exhibits a strong frequency dependence on the excitation laser energy.

What is D peak in Raman?

Abstract. We have studied the D peak in the Raman spectrum of polycrystalline graphite as a function of excitation energy in the range from 1.16 to 4.3 eV. The D peak disperses with excitation energy (≈50 cm−1/eV) and its intensity decreases with increasing laser energy.

What is D and G peak in Raman Spectroscopy?

The G peak is due to the bond stretching of all pairs of sp2 atoms in both rings and chains. The D peak is due to the breathing modes of sp2 atoms in rings [13,26,34].

What is D and G band in graphene?

The ratio of intensity of D/G bands is a measure of the defects present on graphene structure. The G band is a result of in-plane vibrations of SP2 bonded carbon atoms whereas the D band is due to out of plane vibrations attributed to the presence of structural defects.

Why is graphene oxide reduced?

2.3 Reduced graphene oxide (rGO) in order to minimize the amount of oxygen as the oxygen content makes GO more unstable [75]. In its usual oxidized state, GO shows reduced sensitivity due to the oxygen functional groups, making it electrically insulating and not ideal for fabrication of a sensor based on conductance.

What is G and D bands in Raman spectra?

The G band is a result of in-plane vibrations of SP2 bonded carbon atoms whereas the D band is due to out of plane vibrations attributed to the presence of structural defects.

What is a Raman band?

Raman bands of nucleic acids originate from in-plane vibrations of the nucleic acid bases (adenine, guanine, cytosine, thymine and uracil) and from the furanose-phosphate backbone. In general, Raman spectra of DNA or RNA reveal structural information about base stacking and interbase hydrogen bonding interactions.

What is the purpose of graphene oxide?

Graphene oxide (GO), an oxidized derivative of graphene, is currently used in biotechnology and medicine for cancer treatment, drug delivery, and cellular imaging. Also, GO is characterized by various physicochemical properties, including nanoscale size, high surface area, and electrical charge.