Recent Advances in Laser Utilization in the Chemical Modification of Graphene Oxide and Its Applications

Abstract

the manipulation of graphene and its derivatives occupy a relatively insignifi cant part, i.e., less than 1%. The fi rst publications on graphene modifi cation with laser irradiation appeared in 2008, however, since 2010, the number of publications has risen exponentially.Graphene oxide (GO) has emerged as a versatile material for nanocarbon research. Several types of oxygen-containing functional groups present on the basal plane, and the sheet edge allows GO to interact with a broad range of organic and inorganic materials. [ 9 ] Furthermore, GO is an abundant and low-cost material synthesized from graphite or graphite oxide; it retains a layered structure but, at the same time, it can be characterized by the loss of electronic conjugation caused by the oxy groups at the edge or plane defects. GO has a potential use in energy, [ 10 ] electronics, [ 11 ] molecular sensing areas, [ 12 ] catalysis, [ 13 ] etc. Moreover, it can be reduced chemically or thermally in order to achieve graphenelike properties. [ 14 ] The material produced during such a procedure is usually referred to as "reduced GO" (rGO). However, residual defects such as remnant oxygen atoms, [ 15 ] Stone-Wales defects (pentagon-heptagon pairs), [ 16 ] and holes [ 17 ] appearing due to the loss of carbon (in the form of CO or CO 2 ) from the basal plane [ 18 ] limit the electronic quality of rGO.A laser is a powerful tool which is used for various applications in industry, medicine, science, and material processing. [ 19 ] It is usually employed in different processes such as ablation, etching, cutting of various materials, as well as direct A dramatic rise in research interest in laser-induced graphene oxide (GO) reduction and modifi cation requires an overview of the most recent works on this subject. Typical methods for the recognition and confi rmation of modifi ed graphene and its derivatives, such as Raman, Fourier-transform infra-red (FTIR), X-ray photoelectron (XP), and ultraviolet-visible (UV-vis) spectroscopies, are introduced briefl y in this review. A major part of the survey is devoted to the main modifi cation ways and the laser parameters used in the literature. A discussion of possible reduction and modifi cation mechanisms is also presented. Recent applications, especially in the biomedical fi eld such as cell therapy treatment, as well as signifi cant results of GO modifi cation, are discussed in detail. Finally, perspectives for the application of laser-induced GO modifi cations in passive THz photonics and biomedicine are briefl y addressed.

Enrichment of Pyrrolic Nitrogen by Hole Defects in Nitrogen and Sulfur Co‐Doped Graphene Hydrogel for Flexible Supercapacitors

“…We further probed the chemical structure of the as‐prepared samples by Raman spectroscopy, as shown in Figure i. It is evident that all of the samples have two prominent bands at approximately 1340 cm −1 and 1600 cm −1 , assigned to the D and G bands of carbon, respectively. The intensity ratio of the D and G bands (I D /I G ) for the HGH increased slightly compared to that of the GH, indicating larger graphitic domains or defects in the graphene owing to the introduction of significant defects onto the graphene sheet .…”

Characterization of urea derived polymeric carbon nitride and resultant thermally vacuum deposited amorphous thin films: Structural, chemical and photophysical properties

“…The main band located at 1561 cm −1 in the UVexcited Raman spectrum can be assigned to G-band of amorphous carbon nitrides [78]. The Gband (E 2g symmetry) is associated with in-plane stretching vibrations of carbon atom pairs [78,79]. The D-band (A 1g symmetry, due to in-plane breathing vibration of six-membered rings) must be seen as a shoulder at lower wavenumber site; however this band cannot be resolved in our spectra.…”

Simultaneous nanopatterning and reduction of graphene oxide by femtosecond laser pulses

“…Raman spectroscopy allows the analysis of the structure of the carbon network of the graphene basal plane present in the GO flake [5]. The three most prominent peaks (D band at 1350 cm −1 , G band at 1600 cm −1 and 2D band at 2698 cm −1 ) of the Raman spectra are characteristic for graphene related materials [29].…”

“…Graphene oxide (GO) is a graphene-based material, which can be homogeneously dispersed in solvents and therefore provides an attractive option for cost-effective, large-scale production [3]. Reduction of GO has been proven to be an effective method toward the development of graphene-modified materials which have many possible uses, such as transparent electrodes, sensors, energy devices and biological chips [3][4][5]. Usually, the processing is done in two separate steps, which are reduction of the GO and patterning of the layer.…”