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AIP Conference Proceedings [Author(s) 4TH ELECTRONIC AND GREEN MATERIALS INTERNATIONAL CONFERENCE 2018 (EGM 2018) - Bandung, Indonesia (27–28 July 2018)] - Synthesis, characterization and study of graphene oxide
摘要： Graphene oxide (GO) is known to have some unique properties for various applications. GO is the oxidation form of graphene. It is synthesized from graphite through chemical oxidation. In this research, GO was prepared by using an Improved Hummers’ method from natural graphite powder. In addition, the effects of different reaction time of 12 hours, 24 hours, 48 hours and 72 hours on the GO were studied. Results indicated that different sample sizes of GO possessed different morphologies, attachment of functional groups and absorption peaks in Ultraviolet-Visible (UV-Vis) spectroscopy. GO was characterized by using a Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) spectroscopy, UV-Vis and X-Ray Diffraction (XRD). SEM result showed that the GO were appeared in a platelet-like form as compared with the GO (24 hours) where wrinkled and layered-flakes were seen and crumpled structures were seen on GO (72 hours) surface respectively. In FTIR results, the presence of oxygen-containing functional groups was confirmed in GO (72 hours) as compared with GO (12 hours) where the amount of oxygen-containing functional groups was less. In UV-Vis results, the absorption peak of GO (72 hours) was increased due to the longer oxidation time. By comparing these results, the oxidation of graphite to form GO can be determined accurately. Therefore, this study is a great benefit to provide information for researchers to synthesize high quality of GO for various applications.
关键词： Improved Hummers’ method,Reaction time,Characterization,Graphene oxide
更新于2025-09-23 15:23:52
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Synthesis of Graphene Oxide Nanosheets via Modified Hummers’ Method and Its Physicochemical Properties
摘要： The efficient synthesis of exfoliated graphene oxide nanosheets (GO) via modified Hummers’ method was successfully carried out. The physicochemical properties of GO were determined by Fourier transform infrared spectroscopy (FTIR), UV-visible spectrophotometry (UV-vis), x-ray diffraction analysis (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The graphite was fully oxidized by strong oxidizing agent caused the oxygen-containing functional groups such as C-O-C, C=O, and COOH were introduced into the graphite layers as analyzed by Raman and FTIR. XRD pattern of GO showed 2θ of 12.0o with interlayer spacing ~ 7.37A which describe non uniform crystal structure with the addition of oxygen containing functional groups. UV-vis spectrum of GO exhibit maximum absorption peak at ~ 234 nm corresponding to the aromatic C=C bond with π-π* transition. The morphology of GO was observed to have flake-like shape and less transparent layers by TEM. The properties of synthesized GO suggest high potential in producing the high quality of graphene which is can be applied as the electrocatalyst support for direct methanol fuel cell application.
关键词： Graphene oxide nanosheets,characterization,Hummers’ method,graphite,chemical oxidation
更新于2025-09-23 15:22:29
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Efficient synthesis of graphene oxide by Hummers method assisted with an electric field
摘要： An electric field-assisted Hummers method for the synthesis of graphene oxide (GO) is reported which can enhance the efficiency of oxidation processes, while decreasing destructive effects on the resultant graphite lattice. The electric field varies from 0~167 V/cm was applied outside the reaction system and operated on three temperature stages of Hummers method which use a low dose of oxidizer. The as-prepared GO nanoplate has a layer spacing of 1 nm. This improved method may be important for preparing high-quality GO with low cost and light pollution.
关键词： Graphene,Electric field,Graphene oxide,Hummers method
更新于2025-09-19 17:15:36
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Graphene oxide model with desirable structural and chemical properties
摘要： Due to unique chemical, electrical and optical properties, graphene oxide has been widely used as a promising candidate for many applications. Theoretical GO models developed so far present a good description of its chemical structure. However, when it comes to the structural properties, such as the size and distribution of vacancy defects, the curvature (or roughness), there exist significant gaps between computational models and experimentally synthesized GO materials. In this work, we carry out reactive molecular dynamics simulations and use experimental characteristics to fine tune theoretical GO models. Attentions have been paid to the vacancy defects, the distribution and hybridization of carbon atoms, and the overall C/O ratio of GO. The GO models proposed in this work have been significantly improved to represent quantitative structural details of GO materials synthesized via the modified Hummers method. The temperature-programmed protocol and the computational post analyses of Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, vacancy size and curvature distribution, are of general interest to a broad audience working on GO structures from other synthesis methods and other two-dimensional materials and their composites.
关键词： Chemical properties,Reactive molecular dynamics,Modified Hummers method,Graphene oxide,Structural properties
更新于2025-09-10 09:29:36
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Preparation of reduced Graphene Oxide (rGO) assisted by microwave irradiation and hydrothermal for reduction methods
摘要： Graphite is a natural carbon source that can be used for graphene synthesis because of its abundant availability and relatively low cost. In this research, Graphene Oxide (GO) and reduced Graphene Oxide (rGO) have been prepared through modified Hummers method that uses microwave irradiation and hydrothermal process as reduction methods. This research can be divided into two main steps, i.e. preparation of GO and preparation of rGO. The preparation of GO was done using modified Hummers method that refers to graphite powder oxidation for five days. Then, preparation of rGO was done using two methods, i.e. microwave irradiation for 8 minutes at 1,000 watts and hydrothermal process for 10 hours at 200°C. The characterization of the samples was observed by Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Ultraviolet-Visible Spectroscopy (UV-Vis). XRD pattern of GO sample shows a peak at 2θ = 10.63°, rGO sample from hydrothermal process at 2θ = 25.94°, and rGO sample from microwave irradiation method at 2θ = 25.94° with low intensity and at 2θ = 10.63° that indicates the presence of GO. IR spectroscopy data shows an absorption peak of aromatic C=C at 1,573 cm-1 that indicates rGO formation. SEM images of GO illustrates a structure of stacked flakes. While the morphology of rGO has a structure of stacked flakes that is more transparent than GO. According to UV-Vis spectroscopy, GO and rGO of samples show absorption peak at λmax = 225 nm and λmax = 274 nm, respectively, which indicates π→π* transition of aromatic C=C bond. Based on the results of this study, the preparation of rGO using modified Hummers that combined with hydrothermal reduction method is more effective than microwave irradiation reduction method.
关键词： Graphene Oxide,hydrothermal process,Hummers method,reduced Graphene Oxide,microwave irradiation
更新于2025-09-04 15:30:14