Characterization Of Graphene Oxide Research Articles

Graphene oxide based Gd2O3:Eu3+ nanocomposites: A multifaceted approach to advanced energy storage and bio sensing applications

This investigation delves into the synthesis and characterization of graphene oxide (GO) based gadolinium oxide europium-doped nanocomposites (GO-Gd2O3:Eu3+ (1 mol %) NCs), emphasizing their utility in super capacitors and biosensors. Utilizing a hydrothermal process with graphene oxide, the study enhances Gd2O3 energy storage capabilities, complemented by europium’s luminescent features for real-time monitoring. Structural, morphological, and chemical analyses by X-ray diffraction (XRD), Transmission electron microscopy (TEM), and electrochemical (CH) Analyzer, reveal promising electrochemical performance, reaching specific capacitance values of 512.14 Fg−1 in 1 M H2SO4 electrolyte. The electrodes exhibit commendable rate capability, cycling stability, and a Coulombic efficiency of 94.54 % after 5000 galvanostatic charge–discharge (GCD) cycles. Impedance spectroscopy confirms low charge transfer resistance, contributing to enhanced electrochemical performance. Moreover, the integration of europium imparts luminescent properties, positioning these super capacitors for integrated sensing applications. The luminescence allows real-time monitoring, showcasing the versatility of GO-Gd2O3:Eu3+ based NCs for future technologies, particularly in smart sensors, wearables, and integrated electronics.

Synthesis and characterization of graphene oxide, tin oxide, and reduced graphene oxide-tin oxide nanocomposites

The present study reports the synthesis and characterization of graphene oxide (GO), tin oxide nanostructures, and reduced GO (rGO)-tin oxide nanocomposites. The modified Hummer's method was used for the synthesis of GO. Tin oxide nanoparticles were synthesized by co-precipitation method using SnCl2 as tin source. The rGO-tin oxide nanocomposites were synthesized by hydrothermal method using GO and SnCl2 as tin source. The synthesized nanostructures were characterized using powder XRD, FESEM, EDX spectroscopy, TEM, SAED, FTIR spectroscopy, UV–visible spectroscopy, Raman spectroscopy, and TGA. The XRD pattern of the graphite powder shows intense (002) plane peak at 2θ = 26.78° along with the other graphitic XRD peaks. In addition, XRD peaks at 2θ ∼ 14°, 16.8°, 21.18°, and 24.18° were also observed. The characteristic GO (001) plane peak in the XRD pattern could be not be observed in the oxidative exfoliation GO. The Raman spectrum of the graphite powder shows intense crystalline G band, low-intensity defect related D, multi-layered graphitic flake related 2D-band with intensity ratio ID/IG=0.08 and I2D/IG=0.46. The oxidative exfoliated GO shows the degradation of the graphite XRD peaks, but the characteristic GO (001) plane XRD peak could not be observed. The TEM image shows the formation of GO sheets on the oxidative exfoliation of graphite. The d-spacing obtained from the observed hexagonal SAED pattern of the oxidative exfoliated GO was found to be much lower than graphite d-spacing. Raman, UV–visible, FTIR, and TGA studies indicate the formation of GO under oxidative exfoliation of graphite under Hummer’s method. The band gap values of around 1.70 eV from the UV–visible optical absorption also indicates the formation of graphene in the oxidative exfoliated GO. The observed results indicate the formation of graphene embedded amorphous GO.

Synthesis of multi-layer graphene oxide from HCl-treated coke and Brazilian coals by sulfuric acid thermal exfoliation and ozone oxidation

This study involved the synthesis and characterization of graphene oxide (GO) from mineral coke and bituminous coal. HCl treated and non-HCl treated ultrafine powder obtained from both precursors were treated with H2SO4, followed by thermal treatment, and oxidation with ozone and ultra-sonication for GO production. The synthesized materials were characterized using Fourier transform infrared spectroscopy (FTIR), zeta potential (ZP), particle size distribution (PSD), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The results confirmed the exfoliation of the material primarily at the edges of its structure and the formation of multilayer graphene oxide (GO) from mineral coke and bituminous coal. Furthermore, it was found that carbonaceous materials with graphitic morphology are easier to exfoliate and oxidize, leading to the production of higher quality graphene oxide. Therefore, the GO synthesized from mineral coke exhibited the best quality in this study. The methodology used proposes an innovative approach, offering a faster, more economical, and environmentally friendly synthesis compared to the traditional Hummers method, thereby adding value to other raw materials that can be utilized in this process, such as Brazilian coke and coal.

Fabrication and characterization of graphene oxide (GO)-modified micro-nano composite magnetic microspheres

Addressing the contradiction between the magneto-rheological properties and dispersion stability of MRFs poses a significant challenge in the preparation process. This paper proposes a micro-nano composite material design scheme using graphene oxide as a grafting agent to encapsulate nanoscale magnetite (Fe3O4) particles onto the surface of carbonyl iron powders. The prepared micro-nano composite magnetic microspheres achieve a reduction in density for enhanced stability while ensuring no compromise in magnetic performance. The effectiveness of the preparation process is ensured through the analysis of the microscopic morphology, crystal structure, and elemental characteristics of all process products using Field Emission Scanning Electron Microscopy (FE-SEM), powder X-ray diffraction (XRD), Raman Spectroscopy, and Fourier Transform Infrared Spectroscopy (FTIR). To obtain MRFs more suitable for magneto-rheological damper applications, this study synthesized micro-nano composite MRFs with different base liquids and varying volume fractions. The stability and magneto-rheological properties of each sample were analyzed through visual techniques and rheological testing platforms. The results indicated that micro-nano composite MRFs based on 40% to 50% silicone oil exhibit superior stability in various aspects, including sedimentation stability, redispersion stability, and temperature stability. Additionally, the micro-nano composite MRFs demonstrated significantly enhanced magnetic performance compared to pure micrometer-sized, pure nanometer-sized, and micro-nano hybrid MRFs.

Synthesis and characterization of graphene oxide (GO) for the removal of lead ions in water

The synthesis and characterization of graphene oxide (GO) for water related applications has become an increasing area of research. GO was prepared via Hummer's method, and analysed for structure, morphology, thermal stability, and the ability to remove heavy lead ions from solution. In FTIR analyses, hydroxyl, carboxyl and ester groups were found to be on the structure of GO. XRD showed the interlayer spacing to have increased from graphite to graphene oxide, whereby the average crystallite size of GO was 16.13. Then SEM confirmed the morphology of GO to be exfoliated and wrinkled, with stacked layers. In TGA, EG degraded in a single step, while GO degraded in three distinct steps. When using AAS to analyse the Pb (II) ion intake properties of GO, it showed a maximum adsorption of 98.1% for 600 ppm lead ion solution. The Freundlich isotherm model was consistent with this adsorption, meaning that adsorption took place on a heterogenous surface, on a multilayer basis. The value of n for this isotherm was 0.1474, implying a dominant chemical adsorption. A significant contribution was done to the structure of GO, with its metal adsorption properties clearly portrayed.

Synthesis and characterization of graphene oxide as dielectric material for parallel plate capacitor

Graphite acts as an electrical conductor due to the delocalization of electrons between the surfaces. Graphene oxide (GO) is produced by using graphite via the Hummers method. Reduced GO (rGO) is a form of GO where the oxygen content has been reduced due to chemical, thermal, and other processes. In this study, we have produced a prototype of capacitors containing the synthesized rGO with variation of the rGO mass, i.e.: 0 g., 0,2 g; and 0,8 g. Than we compare the capacitance values obtained from the capacitors using a multitester. Characterizations of the rGO are conducted using XRD, UV-Vis, and FTIR. The results of the UV-Vis test show peak at a wavelength of 300 nm indicating absorption of rGO. The XRD test shows a transition from GO to rGO in an amorphous phase. Finally, the FTIR tests produce transmittance bands from the functional groups of CO2, CO, and OH. This paper shows that the capacitance values of the capacitor using rGO material is greater than using graphite material. It means that rGO is capable of storing more charges than graphite. The highest capacitance value is obtained for the capacitor with 0.2 g rGO, i.e.: 165,02 µF.

Synthesis and characterization of graphene oxide and reduced graphene oxide chemically reduced at different time duration

Synthesis and characterization of graphene oxide and reduced graphene oxide chemically reduced at different time duration

Synthesis process and characterization of graphene oxide (GO) as a strength-enhancing additive in concrete

In this work, a particular type of carbon nano-material, like graphene oxide (GO), is synthesized in different batches by varying oxidation times, ranging from 1 to 4 days. The synthesis process initially starts with the oxidation of commercially available graphite powder and subsequently exfoliates the obtained graphite oxide in an aqueous solution using a high-frequency ultrasonication process. The synthesized GO batches were characterized using different characterization techniques to authenticate the formation of GO. The highly oxidized GO in an aqueous solution was selected and used as a strength-enhancing additive in concrete. The concrete mixes containing highly oxidized GO at the dosage of 0.01% 0.03%, 0.05%, 0.07%, and 0.09%bwoc were prepared to assess the strength and durability parameters. The GO (4 d) with 0.09%bwoc in concrete increases compressive strength by 58%, tensile strength by 41%, and flexural strength by 43% at 56 days. The results proved that the 0.09%bwoc GO dosage in cement concrete could effectively improve mechanical and durability performances compared to other mixes. Furthermore, the results are verified with the microstructural investigation using FE-SEM in secondary electron (SE) and backscattered electron (BSE) mode to monitor the microstructural changes and thickness of the interfacial transition zone (ITZ) during cement hydration.

Thermo-electro-rheological properties of graphene oxide and MXene hybrid nanofluid for vanadium redox flow battery: Application of explainable ensemble machine learning with hyperparameter optimization

Recent research has extensively focused on 2D materials such as graphene oxide (GO) and MXene due to their intriguing properties, significantly advancing nanotechnology and materials research. This experimental study explores the use of a vanadium electrolyte-based hybrid nanofluid (HNF) composed of GO and MXene (90:10) to enhance vanadium redox flow batteries (VRFBs). The synthesis and characterization of GO and Mxene nanoparticles (NPs) were conducted using various techniques. The HNF, produced at different weight concentrations, underwent analysis for stability, rheology, thermal conductivity (TC), and electrical conductivity (EC) within a temperature range of 10–45 °C. The results indicate that the HNF exhibits favorable stability and Newtonian behavior in the specified temperature range. At 45 °C, the HNF achieves a maximum enhancement of 20.5 % in EC and 6.81 % in TC for 0.1 wt% compared to the vanadium electrolyte. Subsequently, a prognostic model was developed using an explainable ensemble LSBoost-based machine learning approach, employing a test dataset and applying 5-fold cross-validation to prevent overfitting. Hyperparameter optimization was achieved using the Bayesian technique. The LSBoost-based prognostic models created for TC, EC, and viscosity (VST) demonstrated high effectiveness, with R2 values of 0.9981, 0.99, and 0.9954, respectively. The prediction errors were minimal, with RMSE values of 0.00089255, 5.553, and 0.09391 for the TC, EC, and VST models, respectively. Similarly, the MAE values were low, at 0.00068948, 4.0919, and 0.06129.

GRAPHENE OXIDE DERIVED FROM CASSAVA PEEL AS A POTENTIAL ADSORBENT FOR TETRACYCLINE REMOVAL FROM AQUEOUS ENVIRONMENT

Due to the increase in bacterial resistance, the presence of antibiotic residues in ambient water is becoming a serious problem. In order to stop antibiotic-related water contamination, graphene oxide has been extensively employed as an advanced adsorbent. In this study, cassava peel was utilized to create graphene oxide, which was then applied as an adsorbent to remove tetracycline. The modified Hummers technique was used to produce graphene oxide, along with an oxidizing agent. Studies have been done on graphene oxide characterization and adsorption process optimization. According to the study, tetracycline removal was best accomplished under settings that included an adsorbent mass of 20 mg, an antibiotic concentration of 10 ppm, a pH of 5, and a contact period of 10 minutes. The adsorbent substance has shown promise in removing tetracycline from aqueous environments.

Controlling the bandgap of graphene oxide via varying KMnO4

This research focuses on the production and characterization of graphene oxide via Modified Hummers' method, with a specific emphasis on controlling oxidizing agent concentration. The study employed various analytical techniques to investigate structural and chemical properties. X-ray diffraction (XRD) revealed significant changes in interplanar spacing (8.3 Å to 14.6 Å), implying structural transformations. Raman spectroscopy inspected defects and layer formation. Field Emission Scanning Electron Microscope (FESEM) depicted structural evolution from multilayer lamellar structures to crumpled nanosheets as oxygen concentration varied. FTIR confirms the increase in intensity of notable oxygen containing functional groups, such as hydroxyl, epoxy and carbonyl groups. UV-VIS spectroscopy in conjunction with Tauc's plot shows an increase in bandgap energy (3.37 eV–3.70 eV), MATLAB modelling provides electronic properties of the material.

Characterization of Graphene Oxide and Reduced Graphene Oxide/Metal Oxide Nanocomposite Thin Films

The rGO/TiO2 nanocomposite was synthesized using graphene oxide and butyl titanate as raw materials in a hydrothermal process. Various samples were produced by varying the duration of the hydrothermal treatment. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to examine the nucleation and growth processes of anatase in the hydrothermal process from the thermodynamics and kinetics perspectives. The structural evolution of titanium dioxide/reduced graphene oxide with hydrothermal time was analyzed. The crystallite size as well as the particle size of the TiO2, rGO and TiO2/rGO decreases with increase in the hydrothermal reaction time.

Characterization of graphene oxide by pulsed UV nanosecond laser irradiation for flexible electrodes

This article focused on the fabrication of a thin film of rGO through pulsed Ultraviolet nanosecond laser irradiation. With the influence of laser power energy, the thickness of the fabricated thin film decreased, the contents of Carbon increased, Oxygen contents decreased, electrical resistance decreased, and a normalized specific surface area increased. When the thin film of GO was exposed to laser-irradiation, leads to the reduction of oxygen and the restoration of sp2 hybridization, resulting in a material with reduced electrical resistance and improved specific surface area. As a result, at 125 mW of laser power energy and 200 mm/s scanning speed of pulsed UV nanosecond laser, the contents of Carbon increased up to 81.6%, Oxygen contents decreased to 11.3%, and normalized specific surface area of 0.97 m2/g with good electrical conductivity was obtained. Therefore, its good electrical properties offer prospects for fabricating flexible electrodes and the practical application of pulsed laser-irradiated rGO substrate films for flexible electronics applications.

Effective reinforcement of plasticized starch by the incorporation of graphene, graphene oxide and reduced graphene oxide

Plasticized starch (PLS) nanocomposite films using glycerol and reinforced with graphene (G) and graphene oxide (GO) were prepared by solvent casting procedure. On one hand, the influence of adding different G contents into the PLS matrix was analyzed. In order to improve the stability of G nanoflakes in water, Salvia extracts were added as surfactants. The resulting nanocomposites presented improved mechanical properties. A maximum increase of 287 % in Young's modulus and 57 % in tensile strength was achieved for nanocomposites with 5 wt% of G. However, it seemed that Salvia acted as co-plasticizer for the PLS. Moreover, the addition of the highest G content led to an improvement of the electrical conductivity close to 5 × 10−6 S/m compared to the matrix.On the other hand, GO was also incorporated as nanofiller to prepare nanocomposites. Thus, the effect of increasing the GO content in the final behavior of the PLS nanocomposites was evaluated. The characterization of GO containing PLS nanocomposites showed that strong starch/GO interactions and a good dispersion of the nanofiller were achieved. Moreover, the acidic treatment applied for the reduction of the GO was found to be effective, since the electrical conductivity was 150 times bigger than its G containing counterpart.

Crystal Structure Analysis of Graphene Oxide based on Bamboo “Betung” Synthesized By Modi-Fied Hummer Method

Bamboo is a non-timber forest product with a very large population in Indonesia. One of them is bamboo betung which can be found from the lowlands to the highlands but has not been used properly. Therefore, research was conducted to utilize bamboo betung to benefit the society. In this study, the synthesis of graphene oxide (GO) from bamboo betung stems will be carried out. The purpose of GO synthesis to further observe the crystal structure and crystal size of GO itself because it can be applied in various fields such as wave absorbers, radio frequency electronics, data display panels, and photovoltaic cells. GO synthesis was carried out using the Modified Hummers Method. The sintering temperatures used in this study were 300oC, 350oC, 400oC and 4500C. GO characterization was carried out using XRD and FTIR to reveal the system of crystal, crystal structure, and size, in addition functional groups, and phases of graphene oxide. GO has an average crystal size of 23.30165 nm as the largest average crystal size. GO layer is formed due to the bond between Carbon (C), Hydrogen (H) and Oxygen (O). GO Layer can be typed at any temperature variations carried out..

Graphene oxide–MnFe2O4 nanohybrid material as an adsorbent of Congo red dye

The aim of this work is the synthesis and characterization of graphene oxide (GO)–MnFe2O4 nanohybrid material, as well as the study of its performance in the removal of Congo red (CR) dye from aqueous solutions. The GO–MnFe2O4 was prepared via a three-step method. Firstly, GO was produced via a modified Hummers' method, using graphite powder as starting material. Subsequently, GO was functionalized with ionic surfactants, cetyltrimethylammonium bromide and poly(sodium-4-styrenesulfonate). Following this, the functionalized GO was decorated with magnetic MnFe2O4 nanoparticles via an electrostatic self-assembly process using a solvothermal treatment at 200 °C for 12 h. The as-prepared GO–MnFe2O4 nanohybrid material was characterized by several techniques: X-ray diffraction analysis, Fourier-transform infrared spectroscopy, micro-Raman spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, and high-resolution transition electron microscopy with energy-dispersive spectroscopy mapping. The adsorption performance of GO–MnFe2O4 in the removal of CR dye was evaluated at different initial CR concentrations and contact times using an ultraviolet–visible spectrophotometer. In addition, its recyclability performance was investigated for 10 cycles. It is noteworthy that even after the last cycle, the removal efficiency of GO–MnFe2O4 exceeded 65%, indicating that the adsorbent had very good reusability. Finally, the Freundlich isotherm model yielded a better fit for the adsorption data, compared to Langmuir, while adsorption of CR by GO–MnFe2O4 showed pseudo-second-order kinetics.

Synthesis and characterization of graphene oxide and reduced graphene oxide membranes for water purification applications

Synthesis and characterization of graphene oxide and reduced graphene oxide membranes for water purification applications

Synthesis of ultra-thin graphene oxide/ reduced graphene oxide nanocomposites and examine their properties

Graphene oxide and reduced graphene oxide become center of attraction of researchers for last two decades due to its structural and morphological properties which contribute a unique ability to it. By the incorporation of graphene oxide (GO) or reduced graphene oxide (r-GO) into the polymer matrix makes extraordinary change in its general properties to extraordinary properties. The production of GO and r-GO in large scale with cost effecting way is still become challenge. This present work describes the preparation and characterization of GO incorporated Poly vinyl alcohol (PVA) nanocomposite and r-GO incorporated PVA nanocomposite. By following the modified Hummers reaction technique GO and r-GO. Which is cost effective and easier way GO and r-GO of production. The structural properties of GO and r-GO were examined via UV–vis, FTIR, XRD and SEM. The spectral outcomes of FTIR analysis showed the presence of functional groups in GO and r-GO. The comparative study of GO/r-GO of UV spectra is suggesting for π-π* transition on different wavelength. Various SEM images implied for the formation of ultrathin and homogeneously dispersed PVA supported graphene oxide and reduced graphene oxide nanocomposites. The r-GO is obtained by thermal reduction of GO causing a significant decrease in the amount of oxygen containing groups by which r-GO leads the higher specific surface area with less interlayer separation compared to GO.

Preparation and Characterization of Graphene Oxide from Rice Husk

Preparation and characterization of Graphene Oxide (GO) Fe3O4 nanocomposite has been done. The characterized by XRD showed that graphite,GO and GO-Fe3O4 were amorph. Characterized by FTIR showed that there were a distinctive vibration bands of C-O,C=O, C=C, and OH, and additional bands belong to Fe-O dan Fe-C for the GO-Fe3O4. FESEM analysed showed that GO have smooths and sheets, and fill the wrinkled circle on the surface GO was showed presence of Fe3O4. The diameters of Fe3O4 was 39 nm. Atoms distribution Fe, C, and O of Fe3O4 on the GO sheets showed 15 %. D-band and G-band of GO were 1331 cm-1 dan 1570 cm-1 and D-band of GO-Fe3O4 were 1331 cm-1 based on analyzed using Raman spectroscopy.

Synthesis and Characterization of Graphene Oxide and Chitosan Decorated Nano Zerovalent Iron for Efficient Adsorptive Removal of Hazardous Azo Dye from Aqueous Medium

The main aim of the study was to synthesize nano zerovalent iron (NZVI) modified with graphene oxide (GO) and chitosan (CS) in the form of a magnetic ternary nanocomposite. Three ternary nanocomposites i.e. GO-CS-NZVI, GO-NZVI-CS and CS-NZVI-GO were synthesized to further understand the possible binding tendencies among these components in the final ternary composite. These ternary composites were characterized by FTIR, SEM and EDS techniques to understand the effect of mutual interaction of the three components during synthesis on the overall structure and morphology of the ternary composite. Furthermore, these ternary nanocomposites were employed in the removal of Congo red (an anionic, carcinogenic, azo dye) and also a mixture of dyes Congo red and Rhodamine B (a cationic, carcinogenic dye). A maximum of 98% removal of Congo red and 98.7% removal from the mixture of dyes was observed with ternary nanocomposite GO-CS-NZVI within 30 min. Equilibrium adsorption efficiency (qe) was calculated to be 48.15 and 79 mg/g for Congo red and mixture of dyes (Congo red & Rhodamine B), respectively. A comparative analysis of bare NZVI with these ternary nanocomposites was also conducted to further understand the effect of modification of NZVI with graphene oxide and chitosan on the structure, morphology and its dye removal efficiency.