Combination Of Graphene Oxide Research Articles

Graphene oxide-catalyzed microwave-assisted esterification of oleic acid to biodiesel

The combination of graphene oxide (GO) catalyst and microwave (MW) heating was applied for the esterification of oleic acid with methanol to synthesize methyl oleate. GO was synthesized using the modified Hummers method from graphite powder and characterized by various instrumental methods. To optimize the reaction parameters, reaction temperature, reaction time, methanol-oleic acid molar ratio, and catalyst amount were investigated. An oleic acid conversion of 96.2% was achieved in a reaction time of 1 h at a reaction temperature of 100 °C, using a methanol-oleic acid molar ratio of 9:1 and 5 wt% of GO. In addition, to compare MW heating and conventional heating on the efficiency of esterification, the esterification reaction was carried out with conventional heating under optimized conditions. Finally, the catalytic effect of GO in the conversion of waste cooking oil (WCO) into biodiesel was investigated.

Amphiphilicity evolution in self-assembled carbon-based nanostructures for stabilizing different types of Pickering emulsions

ABSTRACT Carbon-based nanostructures have been firmly established as highly scalable and versatile platforms, which have found extensive applications in several fields of multifunctional nanocomposites, energy storage, environment protection, and electronics device. Pickering emulsion template method is one of the efficient strategies for assembling metastable carbon nanomaterials into stable macroarchitectures. Here, the combination of graphene oxide (GO) and carbon nanotubes (CNTs) was chemically and continuously treated with 2-ethyl-4-methylimidazole (EMI) to acquire tunable wettability. The hybridization of CNTs and reduction of GO can make the as-synthesized carbon nanohybrids be capable of stabilizing oil-in-water (O/W) and water-in-oil (W/O) Pickering emulsions, respectively. The major shift in the type of Pickering emulsion is conveniently implemented through the catalytic reduction of GO by EMI. The sp2-hybridized carbon networks self-assembled with CNTs and reduced graphene oxide (RGO) are intentionally located at the biphasic liquid interface of different types of Pickering emulsions, which can endow the architecture elaborated from Pickering emulsion strategy with multiple functionalities.

Efficient Removal of Representative Chemical Agents by Rapid and Sufficient Adsorption via Magnetic Graphene Oxide Composites

Chemical agents pose a significant threat to social security, highlighting the crucial role of representative chemical agents adsorption in ensuring the safety our environment. This study explored the application of Magnetic Graphene Oxide Nanoplatelet Composites (MGONCs) in adsorbing the representative chemical agents such as Lewisite (L), O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX), Sarin (GB), and Soman (GD). MGONCs were synthesized through a physical blending method, with the combination of graphene oxide (GO) and Fe3O4 nanoparticles at a mass ratio of 1:1. Optimization of the adsorption process involved investigating the effects of contact time, temperature, and adsorbent dosage. Remarkably, the adsorption rate of L and VX exceeded 99% when the dosage of MGONCs was 2.5 mg, with a contact time of 30 s at room temperature. Furthermore, GB and GD achieved maximum adsorption rates after a contact time of 20 min, with the dosages of MGONCs at 10 mg and 20 mg, respectively. Characterization of the magnetic composite was accomplished through XRD, TEM, VSM, FTIR, TGA, and BET analyses. Kinetical analysis revealed that the adsorption mechanism of GB and GD on MGONCs followed pseudo-second-order (PSO) kinetics, exhibiting a high regression coefficient. The calculated qe values were 0.103125 mg/g and 0.081349 mg/g, respectively. This research demonstrated the feasibility of utilizing MGONCs as highly efficient adsorbents for representative chemical agents, particularly in on-site sampling scenarios.

Designing effective enhanced oil recovery fluid: Combination of graphene oxide, D118 SuperPusher, and Chuback surfactant

Enhanced oil recovery (EOR) is one of the most essential branches of petroleum engineering and aims to maximize oil extraction from reservoirs. This research focuses on the utilization of graphene oxide (GO) in combination with a D118 SuperPusher compound and a natural surfactant (Chuback) to enhance oil recovery. The objective is to optimize the efficiency of the EOR process through a multi-component approach. The application of Chuback leads to a substantial decrease in interfacial tension (IFT), particularly in carbonate rock formations. This is attributed to the unique characteristics of carbonate rocks, which exhibit greater susceptibility to wettability alterations. Moreover, GO nanoparticles (NPs) were synthesized, then characterized and incorporated into the surfactant-polymer system, creating surfactant-polymer-nanoparticle (SPN) fluids. The selection of optimum fluid formulations for the EOR process is facilitated through the utilization of Design Expert, a statistical software tool. Factors such as surfactant concentration, polymer concentration, NPs concentration, and two types of salt concentrations are specifically chosen as variables that can influence the fluid's performance during the flooding step. Parameters including IFT, contact angle (CA) (which affects wetting behavior), and shear viscosity (which impacts fluid flow) are considered responses. The efficacy of the suggested fluid formulation for EOR is validated through core flooding investigations. Core flooding investigations validated the efficacy of the suggested fluid for EOR, with recovery factors of up to 30% and 56% in sandstone and carbonate core samples, respectively. These findings underscore the potential of the proposed approach to significantly enhance oil recovery from both sandstone and carbonate reservoirs.

Combination of Graphene Oxide and Rhizobium Improved Soybean Tolerance in Saline-Alkali Stress

Soybean (Glycine max L.) is the most important crop plant in the world. Soil saline-alkali seriously inhibits soybean yield and quality. This study aims to investigate the impact of graphene oxide (GO) and Rhizobium (Rh) on the expression of soybean-related genes as well as the growth and yield under saline-alkali stress. The results show that GO + Rh-treated increased the number of root nodules by 5.43 times compared with the control (Ctrl), the total nitrogen content and root system parameters of plants were also significantly improved. GO + Rh-treated reduced the Na+/K+ ratio and the osmotic substances, while the activities of antioxidant enzymes SOD, POD, CAT and APX in GO + Rh-treated soybean plants increased significantly by 69.18%, 69%, 75.64% and 48.38% compared with the control plants. The REC, MDA and H2O2 content decreased significantly by 46.73%, 42.80% and 43.53%. In addition, GA3 content, among all related saline-alkali hormones, was increased by 100.20% compared with the Ctrl. The expression level of GmGBP1, a key gene for GA3 synthesis, at most increased 6.42 times compared to the Ctrl. The results further reveal that GO + Rh-treated obviously improves the yield traits of soybean plants, which confirms that GO + Rh-treated could be effective in enhancing soybean tolerance to saline-alkali stress. Our findings provide a new strategy for improving the saline-alkali tolerance of soybean, as well as a new perspective for exploiting and utilizing large-area saline-alkali soil.

The combination of graphene oxide and preservatives can further improve the preservation of cut flowers.

It is reported that the use of nanomaterials can extend the vase life of fresh-cut flowers. Graphene oxide (GO) is one of these nanomaterials that aid in promoting water absorption and antioxidation during the preservation of fresh-cut flowers. In this investigation, the three mainstream brands of preservatives commercially available on the market ("Chrysal," "Floralife," and "Long Life") in combination with low concentrations of GO (0.15 mg/L) were used to preserve fresh-cut roses. The results showed that the three brands of preservatives had different degrees of freshness retention. Compared to the preservatives used alone, the combination of low concentrations of GO with the preservatives, especially in the L+GO group (with 0.15 mg/L GO added in the preservative solution of "Long life"), further improved the preservation of cut flowers. L+GO group showed less level of antioxidant enzyme activities, lower ROS accumulation and cell death rate, and higher relative fresh weight than the other groups, implying a better antioxidant and water balance abilities. GO attached to the xylem duct of flower stem, and reduced the blockage of xylem vessels by bacteria, which were determined by SEM (scanning electron microscopy) and FTIR (Fourier transform infrared) analysis. XPS (X-ray photoenergy spectra) analysis results proved that GO could enter the interior of flower stem through xylem duct, and when combined with "Long Life," the anti-oxidation protection ability of GO was enhanced, thus delaying ageing, and greatly extending the vase life of fresh-cut flowers. The study provides new insights into cut flower preservation using GO.

Removal of Arsenic(III) from Water with a Combination of Graphene Oxide (GO) and Granular Ferric Hydroxide (GFH) at the Optimum Molecular Ratio

The occurrence of arsenic in water is a global problem for public health. Several removal technologies have been developed for arsenic removal from water, and adsorption onto iron oxy-hydroxides is the most widely used technique. Granular ferric hydroxide (GFH) has been used mainly for As(V) removal, but it has the disadvantage that it can create a problem with the residual concentration of iron in the water. Moreover, graphene oxide (GO), which contains a large amount of reactive oxygen, exhibits high adsorbing capacity. In this study, the combined use of GO and GFH as adsorbent materials in different molar ratios was investigated in order to achieve the maximum As(III) removal from aqueous solutions. The effect of the adsorbent’s dosage, pH value, contact time, initial As(III), and different molar ratios of GO/GFH was examined. As depicted, the presence of GFH enhances the use of GO. In particular, the molar ratio of GO/GFH 2:1 (i.e., 0.2 g/L GO and 0.1 g/L GFH) is chosen as optimal at pH value 7.0 ± 0.1, while the removal percentage increased from 10 % (absence of GFH) to 90% with the simultaneous addition of GFH. Freundlich isotherm and pseudo-second-order kinetic models described the experimental data adequately and the highest adsorption capacity that was achieved was 22.62 μg/g.

A novel photoelectrochemical sensor based on flower-like SnS2, sea urchin-like AgBiS2 and graphene oxide nanocomposite film for efficient and sensitive detection of acetaminophen in lake water samples

As an emerging detection technology, photoelectrochemical sensors have been widely noticed for their unique technical features. Among others, the technology has been widely used in the fields of drug, biological antibody or antigen and contaminant detection. Secondly, acetaminophen, as a novel environmental pollutant, is difficult to be degraded in the ecosystem, which in turn causes serious impacts on the ecosystem. Therefore, in this work, we designed a photoelectrochemical sensor based on a composite film of flower-like SnS2, sea urchin-like AgBiS2 and graphene oxide for the detection of acetaminophen in water samples. Among them, graphene oxide, as a two-dimensional carbon-based material, can immobilize other photoelectric materials well. In addition, the flower-like SnS2 and sea urchin-like AgBiS2 can enhance the intensity of the photoelectric response due to their synergistic effect. Notably, the combination of graphene oxide with SnS2 and AgBiS2 revealed an exponential increase in the photoresponse intensity, indicating that SnS2/AgBiS2/GO has a satisfactory photoresponse intensity. At the same time, the photoelectrochemical sensor exhibited sensitive detection performance (LOD = 4 nM) and a wide detection range (0.01–50 μM) for acetaminophen under optimal detection conditions. Moreover, it also showed excellent detection performance in the detection of actual water samples, indicating that it can be applied to the detection of acetaminophen in lakes.

Gold Nanoparticles Decorated with Multi-Walled Carbon Nanotubes/Graphene Oxide for Voltammetric Determination of Dopamine in the Presence of Acetaminophen

We developed an electrochemical sensor by combination of Graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) then decorated with Au-nanoparticles (AuNPs) by an electrodeposition process for detection of dopamine (DP) in the presence of acetaminophen (AC). The electrochemical properties of MWCNT/GO- AuNPs/GCE were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV).The results displayed that Au nanoparticles were well jointed onto MWCNT/GO nanocomposite. The electrochemical responses displayed the prepared sensor showed enhanced electrocatalytic activity for the detection of DP inthe presence of acetaminophen (AC). Under optimum conditions, the proposed sensorpresented a linear response based on the DP concentration in the range of 1.0 to 165 μM with a detection limit of 0.07 μM using the differential pulse voltammogram (DPV) method.Moreover, this proposed sensor displayed a linear range concentration of AC ranging from 3 to 200.0 μM and detection limit of 0.061 μM. Also, the prepared sensor indicated excellent sensitivity and selectivity for the DP determination in the presence of AC in real samples.

Experimental and theoretical study of the effect of different functionalities of graphene oxide/polymer composites on selective CO2 capture.

There is a constant need for versatile technologies to reduce the continuously increasing concentration of CO2 in the atmosphere, able to provide effective solutions under different conditions (temperature, pressure) and composition of the flue gas. In this work, a combination of graphene oxide (GO) and functionalized waterborne polymer particles was investigated, as versatile and promising candidates for CO2 capture application, with the aim to develop an easily scalable, inexpensive, and environmentally friendly CO2 capture technology. There are huge possibilities of different functional monomers that can be selected to functionalize the polymer particles and to provide CO2-philicity to the composite nanostructures. Density functional theory (DFT) was employed to gain a deeper understanding of the interactions of these complex composite materials with CO2 and N2 molecules, and to build a basis for efficient screening for functional monomers. Estimation of the binding energy between CO2 and a set of GO/polymer composites, comprising copolymers of methyl methacrylate, n-butyl acrylate, and different functional monomers, shows that it depends strongly on the polymer functionalities. In some cases, there is a lack of cooperative effect of GO. It is explained by a remarkably strong GO-polymer binding, which induced less effective CO2-polymer interactions. When compared with experimental results, in the cases when the nanocomposite structures presented similar textural properties, the same trends for selective CO2 capture over N2 were attained. Besides novel functional materials for CO2 capture and a deeper understanding of the interactions between CO2 molecules with various materials, this study additionally demonstrates that DFT calculations can be a shorter route toward the efficient selection of the best functionalization of the composite materials for selective CO2 capture.

Effect of nanoparticle based intra-canal medicaments on root dentin micro-hardness.

Complete eradication of bacterial infection from the root canal with minimum or no effect on the microhardness of the dentin is desirable for the success of endodontic treatment. The effect of nanoparticle based intracanal medicaments on the root dentine microhardness was assessed. The medicaments used were combination of calcium hydroxide - silver nanoparticles, Combination of graphene oxide - silver nanoparticles, Calcium hydroxide and a control group. Vickers hardness value were evaluated and compared at coronal, middle and apical third level. Graphene oxide - silver nanoparticles based intracanal medicament showed least effect on the microhardness of the root dentin compared to calcium hydroxide and calcium hydroxide combined with silver nanoparticle based intracanal medicaments.

Hyperbranched graphene oxide structure-based epoxy nanocomposite with simultaneous enhanced mechanical properties, thermal conductivity, and superior electrical insulation

The combination of graphene oxide (GO) nanosheets and polymer matrix provides an opportunity to synthesize polymer composites with excellent engineering application performance. However, the preparation of high-performance GO-based composites is difficult because the nano-scaled GO is easily agglomerated, and the weak interface bonding force between the GO and polymer. Herein, a simple and effective method for preparing GO-based composites via hyperbranched polymer (HPB) grafting is presented. The resulting HPB-GO has uniformly dispersed in the epoxy resin (EP) matrix and combines with the matrix through chemical bonds, which has a strong interfacial acting force and improves the load transfer efficiency of the matrix to HPB-GO. Thus, the resultant EP/HPB-GO nanocomposite exhibited superior mechanical properties with a dramatic increase with only 0.2 wt% HPB-GO loading, the impact strength, the tensile strength, and the compression strength, i.e., 58.53%, 83.29%, and 57%, respectively, when compared to pure epoxy resin. Meanwhile, the nanocomposite exhibits an 80% increase in thermal conductivity (0.32 W m−1 K−1). Moreover, outstanding electrical insulation performance is obtained. The ultra-low content of HPB-GO significantly improves the performance of epoxy resin, which provides an economical and effective method to broaden the application of epoxy resin in engineering.

Combination of graphene oxide and platelet-rich plasma improves tendon-bone healing in a rabbit model of supraspinatus tendon reconstruction.

The treatment of rotator cuff tear is one of the major challenges for orthopedic surgeons. The key to treatment is the reconstruction of the tendon–bone interface (TBI). Autologous platelet-rich plasma (PRP) is used as a therapeutic agent to accelerate the healing of tendons, as it contains a variety of growth factors and is easy to prepare. Graphene oxide (GO) is known to improve the physical properties of biomaterials and promote tissue repair. In this study, PRP gels containing various concentrations of GO were prepared to promote TBI healing and supraspinatus tendon reconstruction in a rabbit model. The incorporation of GO improved the ultrastructure and mechanical properties of the PRP gels. The gels containing 0.5 mg/ml GO (0.5 GO/PRP) continuously released transforming growth factor-β1 (TGF-β1) and platelet-derived growth factor (PDGF)-AB, and the released TGF-β1 and PDGF-AB were still at high concentrations, ∼1063.451 pg/ml and ∼814.217 pg/ml, respectively, on the 14th day. In vitro assays showed that the 0.5 GO/PRP gels had good biocompatibility and promoted bone marrow mesenchymal stem cells proliferation and osteogenic and chondrogenic differentiation. After 12 weeks of implantation, the magnetic resonance imaging, micro-computed tomography and histological results indicated that the newly regenerated tendons in the 0.5 GO/PRP group had a similar structure to natural tendons. Moreover, the biomechanical results showed that the newly formed tendons in the 0.5 GO/PRP group had better biomechanical properties compared to those in the other groups, and had more stable TBI tissue. Therefore, the combination of PRP and GO has the potential to be a powerful advancement in the treatment of rotator cuff injuries.

Green synthesis of graphene gold nanocomposites for optical sensing of ferritin biomarker

The combination of graphene oxide with gold nanoparticles offers enhanced optical properties with strong surface plasmon resonance, good biocompatibility, improved stability and ultrasensitive detection. This study aims to synthesize ecofriendly graphene oxide gold nanocomposites for sensing of ferritin biomarker, which is vital for diagnosing anemia as well as severe COVID conditions. Herein, an affordable and label free technique was proposed for detection of ferritin. The graphene oxide gold nanocomposites are synthesized by a simple one pot chemical reaction utilizing natural reducing agents. The alterations in the optical spectral characteristics of graphene gold nanocomposites upon interaction with the Fe3+ ions as well as ferritin protein are investigated. The proposed label free technique achieved a limit of detection of 1 μM for Fe3+ ions and 1 μg/ml for Ferritin protein.

Enhancement of thermal and mechanical properties of PMMA composites by incorporating mesoporous micro-silica and GO

The application of polymer-based composite materials is on the rise due to their enhanced thermal and mechanical properties compared to polymers themselves. For the first time in this study, the combination of graphene oxide (GO) and mesoporous micro-silica particles (with varying pore sizes) was used as fillers into PMMA matrices via in-situ bulk polymerization with ultrasonication. Two types of mesoporous silica were used at a fixed amount of 3 wt% with varying GO composition from 0.1 wt% to 1.2% to investigate the synergistic effect of GO and silica and increment of pore size of silica filler on the thermomechanical properties of the composites. The glass transition temperature Tg, thermal stability (the temperature at 10% and 60% weight loss) Td10 and Td60 of the same composite were increased by 21.5 °C, 46.5 °C, and 32.3 °C, respectively, compared to that of neat PMMA. Its tensile strength was increased remarkably by 329% compared with the PMMA. This work offers the possibility of further enhancement of thermal and mechanical properties of polymer-based composites by incorporating more than one filler with diverse properties.

Thermal process enhancement of HNCPCM filled heat sink: Effect of hybrid nanoparticles ratio and shape

The present study based on the numerical investigation of a hybrid nanocomposite phase change material (HNCPCM) filled heat sink for passive cooling of electronic devices. The combination of graphene oxide (GO) and silver (Ag) hybrid nanoparticles are added inside the RT-28HC to enhance thermal performance. The volume fraction ratios of Ag:GO are varied from 0:0, 0:4, 1:3, 2:2, 3:1 and 4:0. Four different shape factor values of 3.7, 4.9, 5.7 and 16.1 of Ag-GO are varied. The transient simulations are carried out to solve the governing equations using the finite volume method scheme. The results depicted that employing HNCPCM has better heat transfer enhancement compared to the pure PCM because of the addition of nanoparticles. The results showed that adding the Ag-GO inside the RT-28HC improved the thermal conductivity and uniformity in the melting process compared to the RT-28HC based heat sink. With the addition of Ag-GO, melting time of HNCPCM filled heat sink is reduced and heat transfer rate in increased. The optimum ratio of 1:3 of Ag:GO nanoparticles and shape factor value of 16.1 show the higher thermal conductivity of 0.348 W/m.K, 12.93% reduction in melting time, 8.65% enhancement in heat storage capacity and rate of heat transfer.

Graphene Oxide/Fe2O3 Nanocomposite as an Efficient Catalyst for Thermal Decomposition of Ammonium Perchlorate via the Vacuum-Freeze-Drying Method.

The combination of graphene oxide (GO) and iron oxide (Fe2O3) may induce property enforcement and application extension. Herein, GO/Fe2O3 nanocomposites were synthesized via the vacuum-freeze-drying method and used for the thermal decomposition of ammonium perchlorate (AP). A series of characterization techniques were applied to elucidate the as-obtained nanomaterial's physicochemical properties. These results show that the treated GO is consistent with the pristine GO after the freeze-drying treatment. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses show that iron oxide nanoparticles are anchored on and between the GO sheets. The catalytical effect investigation on AP with different Fe2O3: GO ratios indicates that the high-temperature decomposition temperature of AP could be decreased by a temperature as high as 77 °C compared to pure AP accompanied by 3 wt % GO/Fe2O3 nanocomposite which proves the high catalytic performance of the nanocomposites. The first-principles calculation was employed to elaborate the synergistic effect, and the findings demonstrate that the presence of graphene in the catalyst can enhance the catalytic effect via reducing the activation energy barrier by ∼17% in the reaction of AP thermal decomposition.

Intensifying separation and antifouling performance of PSf membrane incorporated by GO and ZnO nanoparticles for petroleum refinery wastewater treatment

The fouling formation on the membrane’s surface has limited the membrane-based separation in industrial activities such as wastewater reclamation and seawater desalination. The nanomaterials' incorporation has been developed to enhance membrane performance. In this study, the combination of graphene oxide (GO) and zinc oxide (ZnO) nanoparticles to PSf membrane to improve the membrane performances to treat the petroleum refinery wastewater (PRW) was performed. The SEM-EDX result shows the presence of both GO and ZnO nanoparticles on the membrane's surface. They also produced the porosity of 83.00 ± 1.18 % for PSf/GO/ZnO, which was higher than the neat PSf with 52.20 ± 0.28 %. The FTIR and XRD result has confirmed the presence of GO and ZnO in the membrane that caused the increment in hydrophilicity and mechanical strength. The addition of GO and ZnO nanoparticles has reduced the water contact angle from 80° to 52° and increased water uptake ability from 16 % to 75 % compared to the neat PSf. It has also resulted in the highest permeate flux and pollutant removal compared to the other membranes with a maximum permeate flux of 35.03 L.m−2.h−1 and a rejection value 70.21 ± 2.33 % for total dissolved solids (TDS) and 74.68 ± 0.88 % for chemical oxygen demand (COD). The fouling resistance evaluation showed the addition of GO and ZnO nanoparticles successfully reduced the resistance during filtration, indicating a reduction in fouling tendency on the membrane's surface. These phenomena are proven by the antifouling potential analysis at the addition of GO and ZnO nanoparticles was exhibited the highest flux recovery ratio up to 90.44 ± 1.22 %.

Mechanically Intensified and Stabilized MXene Membranes Via the Combination of Graphene Oxide for Highly Efficient Osmotic Power Production

Mechanically Intensified and Stabilized MXene Membranes Via the Combination of Graphene Oxide for Highly Efficient Osmotic Power Production

Graphene sheet-encased silica/sulfur composite cathode for improved cyclability of lithium-sulfur batteries

The “shuttle effect” of polysulfides is a serious issue, resulting in a decrease in the life-cycle of lithium-sulfur (Li-S) batteries. To inhibit the shuttle effect, a combination of graphene oxide and silica has been adopted in this work. Here, two different ratios of sulfur/silicon dioxide/partially reduced graphene oxide (S/SiO2/prGO - 70:20:10 and 70:10:20) composite materials were prepared via a melt diffusion method and were used as a cathode for a Li-S battery. The wrinkled sheets of partially reduced graphene oxide not only provide a conductive network for electron transport, but also ease the volume changes of active material during cycling. The 20 wt% of prGO present in the S/SiO2/prGO cathode delivers initial discharge capacity of 783 mAh g−1 at 0.2 C and remains at 491 mAh g−1 over 300 cycles, with low capacity decay rate of 0.12% per cycle. The better electrochemical performance indicates that the electrode containing 20 wt% of prGO with silica effectively suppresses the “shuttle effect” of polysulfide dissolution.