Graphene Oxide Research Articles

Exploring potential of graphene oxide as an alternative antiviral approach for influenza A H1N1.

Aim: Graphene oxide (GO), known for its distinctive physicochemical properties, shows promise as a nanomaterial capable of combating infectious agents. This study investigates the efficacy of GO nanoparticles in restricting influenza A H1N1 replication in MDCK cells.Methods: GO nanoparticles were synthesized. After evaluating the toxicity of GO nanoparticles, the antiviral activity of the highest nontoxic concentration of GO against influenza A H1N1 in MDCK cells was studied.Results: GO treatments resulted in substantial decreases in virus titers, as shown via hemagglutination assay, TCID50 assay and real-time PCR analysis.Conclusion: This study emphasizes that GO nanoparticles have a high level of effectiveness against influenza A H1N1 viruses, making them an intriguing option for various antiviral uses.

Atomistic Modeling of Natural Gas Desulfurization Process Using Task-Specific Deep Eutectic Solvents Supported by Graphene Oxide

This study employs Density Functional Theory (DFT) calculations and traditional all-atom Molecular Dynamics (MD) simulations to reveal atomistic insights into a task-specific Deep Eutectic Solvent (DES) supported by graphene oxide with the aim of mimicking its application in the natural gas desulfurization process. The DES, composed of N,N,N′,N′-tetramthyl-1,6-hexane diamine acetate (TMHDAAc) and methyldiethanolamine (MDEA) supported by graphene oxide, demonstrates improved efficiency in removing hydrogen sulfide from methane. Optimized structure and HOMO-LUMO orbital analyses reveal the distinct spatial arrangements and interactions between hydrogen sulfide, methane, and DES components, highlighting the efficacy of the DES in facilitating the separation of hydrogen sulfide from methane through DFT calculations. The radial distribution function (RDF) and interaction energies, as determined by traditional all-atom MD simulations, provide insights into the specificity and strength of the interactions between the DES components supported by graphene oxide and hydrogen sulfide. Importantly, the stability of the DES structure supported by graphene oxide is maintained after mixing with the fuel, ensuring its robustness and suitability for prolonged desulfurization processes, as evidenced by traditional all-atom MD simulation results. These findings offer crucial insights into the molecular-level mechanisms underlying the desulfurization of natural gas, guiding the design and optimization of task-specific DESs supported by graphene oxide for sustainable and efficient natural gas purification.

The influence of metal ions on aqueous dispersions of graphite oxide

ABSTRACT The residual metallic impurities in the graphite oxide (GO) dominate their properties and have a negative influence on the potential applications. The swelling of the GO suspensions is mainly affected by electrostatic forces and special interactions between water molecules, metal ions and hydrophilic groups. Bivalent and trivalent cations give rise to ionic crosslinking of the charged network within the particles. The CaCl2 solution has the best purification effect. A new purification method is proposed in the purification process, the origin metal ions in GO suspensions are replaced by homogeneous metal ions first, and GO suspensions are desalted by electrodialysis device. Free ionic calcium is removed by electrodialysis, and only the calcium that interact with GO particles is remained. The content of fixed calcium is 0.0049 g/g (nearly clear) after washing with 1.5 mmol/L CaCl2 solution and electrodialyzing for 20 min. The new method improves the purification efficiency and save energy.

Optimisation of laser surface ablation of alumina/GO coating on AZ31D magnesium alloy using Cuckoo Search Algorithm method

ABSTRACT Graphene oxide (GO) and alumina (Al2O3) work in concert to give magnesium alloys advantageous surface qualities and protection from adverse environments. This paper aims to investigate the effect of laser surface treatment on plasma sprayed alumina-graphene oxide (GO) coating on AZ31D magnesium alloy. Key ablation quality responses; HAZ width, surface roughness and ablation rate were correlated with laser parameters using the Response Surface Methodology and optimised using the metaheuristic Cuckoo Search Algorithm Method. Laser power significantly influenced all ablation characteristics of the composite coating. The addition of 1.5 wt% GO in the alumina coating caused a significant reduction in HAZ width (43.32%), surface roughness (25.11%) and ablation rate (76.58%) when treated with optimal combinations of laser power (8 W), scanning speed (950 mm/s) and frequency (78.2 kHz). The surface quality was characterised by smooth textures, and resolidified splats along with deep pits when ablated with lower and intermediate power whereas surfaces ablated with higher power showed debonded splats with peripheral surface destruction. While a prominent 2D peak at 16 W confirmed the presence of GO layers during high-power laser contacts, the ID/IG ratio below unity across all specimens indicated minimal defect concentrations.

Electrochemical Reduction of Graphene Oxide on Flexible Interdigitated Electrodes and Its Application as Strain Sensors

This study presents the electrochemical reduction of graphene oxide (GO) to reduced graphene oxide (rGO) directly onto flexible interdigitated gold electrodes and its application as a strain sensor. GO reduction is achieved using cyclic voltammetry (CV). Remarkably, only a single CV cycle transformed GO into rGO to obtain low‐resistance (≈100 Ω) devices. The reduction of GO is confirmed using Raman spectroscopy and electrical measurements. rGO on flexible interdigitated gold electrodes exhibits graphene‐like characteristics when used as electrolyte‐gated field‐effect transistors. The fabricated devices display a gauge factor (GF) of ≈3.7 in the 0–794 με range. This value represents a substantial improvement, ≈60% higher than traditional metallic strain sensors, which have a GF of ≈2.1. Most importantly, the rGO strain sensor exhibits fast response (1.1 s) and recovery (0.92 s) times. The rGO sensor is mounted on a clamp with an adjustable diameter, which reveals exceptional flexibility and bendability without damage or degradation. These results highlight the potential of rGO for advancing strain‐sensing applications, offering promising opportunities for the future of this technology.

Theoretical and experimental study on efficient thorium removal from aquatic environment using phosphate-modified graphene oxide polymeric beads

AbstractThorium is an element of immense importance in nuclear industry due to lower environmental impact compared to fossil fuels and conventional nuclear power. In the present study, highly selective adsorption of Th4+ on phosphate modified graphene oxide polymeric beads was investigated. The interaction of –PO4, –OH and –O– functional groups of graphene oxide with thorium ion was thoroughly investigated using Density Functional Theory. The adsorption induced density difference was utilized to investigate the bonding characteristics. The affinity of the Th4+ ions was obtained as –PO4 > –OH > –O– group of the phosphate modified graphene oxide. Phosphate modified Graphene oxide embedded in Calcium alginate matrix was characterized using ATR-FTIR, XRD, SEM and Raman spectroscopy. Highly efficient (> 93%) uptake of thorium at pH 5 with fast rate of sorption (< 5 min) was observed in the batch sorption studies.

In Situ Synthesis of NPC-Cu2O/CuO/rGO Composite via Dealloying and Microwave-Assisted Hydrothermal Technique

The nanoporous copper (NPC)-copper oxides (Cu2O/CuO)/reduced graphene oxide (rGO) composite structure was synthesized by combining the dealloying process of Cu48Zr47Al5 amorphous ribbons with a microwave-assisted hydrothermal technique at a temperature of 200 °C. The main advantage of the microwave-assisted hydrothermal process is the oxidation of nanoporous copper together with the in situ reduction of graphene oxide to form rGO. The integration of rGO with NPC improves electrical conductivity and streamlines the process of electron transfer. This composite exhibit considerable potential in electrochemical catalysis application, due to the combined catalytic activity of NPC and the chemical reactivity of rGO. Our study relates the transition to n-type rGO in microwave-assisted hydrothermal reactions, and also the development of an electrode material suitable for electrochemical applications based on the p-p-n junction NPC-Cu2O/CuO/rGO heterostructure. To confirm the formation of the composite structure, structural, morphological, and optical techniques as XRD, SEM/EDX, UV-Vis and Raman spectroscopy were used. The composite’s electrochemical properties were measured by EIS and Mott-Schottky analyses, showing a charge transfer resistance (Rp) of 250 Ω and indicating the type of the semiconductor properties. The calculated carrier densities of 4.2 × 1018 cm−3 confirms n-type semiconductor characteristic for rGO, and 7.22 × 1018 cm−3 for Cu2O/CuO indicating p-type characteristic.

Bibliometric Analysis of Publications on the Synthesis of Graphene and Reduced Graphene Oxide in the Scopus Research Platform

Objective: Conduct a bibliometric analysis of articles on the synthesis of graphene and graphene oxide, as well as their applications, from the documents in the last fourteen years. Method: The bibliometric analysis used data from the Scopus database to visualize the main keywords, countries, and journals, addressing the theme of graphene synthesis and its applications over the past 14 years, from 2010 to 2024. Results and Discussion: Using the Bibliometrix software combined with R programming, 1,485 documents published in English were analyzed, which includes articles in review and in their final version. The results demonstrated that despite being a widely explored theme in the scientific community, there is still a growing global relevance. Research Implications: The analysis provided significant data on the development and key trends in academic research. The study revealed a great interest in obtaining reduced graphene oxide and its application in solar cells, as well as the efficiency they produce. Originality/Value: The study aimed to contribute to academic research by demonstrating and analyzing the main trends in graphene synthesis and its applications. Demonstrating its relevance in recent years and the growth in applications in photovoltaic systems.

Nanocellulose‐reinforced, anti‐freezing, highly conductive ionic organic hydrogels for flexible electronic devices

AbstractCurrently, flexible electronic devices based on ionic conductive hydrogels are receiving widespread attention in the field of human health detection. In this paper, a facile one‐pot method is proposed for the preparation of ionic organic hydrogels, in which polyvinyl alcohol (PVA), cellulose nanofiber (CNF), and graphene oxide (GO) are dissolved in dimethyl sulfoxide‐water (DMSO/H2O), and the organic hydrogel is obtained by a freezing–thawing process. The ionic organic hydrogel with excellent properties is then prepared by soaking the hydrogel in a calcium chloride (CaCl2) solution using a salting‐out strategy. The ionic organic hydrogel possesses good tensile (283%) and strength (0.3 MPa), super electrical conductivity (7.72 S/m), and high strain sensitivity [gauge factor (GF) up to 5.22]. Meanwhile, it has excellent anti‐freezing and moisturizing properties. In addition, the ionic organic hydrogels can be used in flexible strain sensors and triboelectric nanogenerators to realize real‐time monitoring of human motion, traceless writing, and energy conversion. It is foreseen that the prepared ionic organic hydrogels provide a feasible method for realizing the long‐term use of wearable electronic devices in extreme environments and daily life.

Study of the effect of N, N-diethyl hydroxyl amine/multi-layered graphene oxide hybrid on reducing cathodic delamination and increasing corrosion resistance of epoxy coating on steel substrate

In this study, a hybrid of multi-layered graphene oxide (MLGO) and oxygen absorbent corrosion inhibitor N, N-diethyl hydroxylamine (DEHA) was investigated. The nano hybrid was prepared in order to reduce the amount of cathodic delamination and increase the corrosion resistance of the epoxy coating. Epoxy coatings were prepared using the optimal percentage of 0.75 wt. % of the nano hybrid with different ratios between MLGO and DEHA like (1:2), (1:1) and (2:1). Mapping energy-dispersive X-ray spectroscopy, thermo gravimetry analysis and Fourier transform infrared (FT-IR) analysis indicated the uniform distribution of the inhibitor throughout the MLGO structure and the hydrogen bond interactions between them. The results of FT-IR spectroscopy: attenuated total reflectance test after six months confirmed the presence and stability of the inhibitor in the coating. Also, the results of 800 h of salt spray test and the long-term electrochemical impedance test after 7 months showed that the epoxy coating, containing MLGO-DEHA (1:2) had the highest corrosion resistance (2.54 × 107 Ω cm2) and the lowest cathodic delamination (15.9%). The results were also confirmed by cathodic delamination and pull-off adhesion tests.

Microwave electromagnetic shielding with free-standing composites based on graphene oxide and silver nanowires

Microwave electromagnetic shielding with free-standing composites based on graphene oxide and silver nanowires

Synergistic Regulation of Phase and Nanostructure of Nickel Molybdate for Enhanced Supercapacitor Performance

Nickel molybdate, which has a relatively high theoretical capacity, demonstrates potential for use in supercapacitors. However, its inferior electrical conductivity and cycling stability have led to poor electrochemical performance. Nanostructure engineering of NiMoO4 is an efficient strategy to overcome its performance limitations as an electrode. Here, a facile approach is reported for the precise phase regulation and nanostructure of NiMoO4 by manipulating the synthesis parameters, including duration, precursor selection, and urea concentration. The electrochemical properties of the electrode materials are also investigated. It is interesting to note that the β-NiMoO4 nanosheets show a decent specific capacity of 332.8 C/g at 1 A/g, surpassing the 252.6 C/g of the α-NiMoO4 nanorods. Furthermore, the supercapacitor device constructed with β-NiMoO4 and reduced graphene oxide hydrogel (rGH) electrodes achieves an acceptable energy density of 36.1 Wh kg−1, while retaining 70.2% after 5000 cycles.

Multi-sensing yarns for continuous wireless sweat lactate monitoring

Textile integrated sensors based on conductive, electrochemically active microfibers can enable inexpensive, nearly invisible distributed sensing of sweat in clothing. Reduced graphene oxide fibers are mechanically robust, conductive, and can be easily functionalized to form a variety of sensors with properties comparable to planar fabricated sensors, given their ability to work both as electrical interconnections and as a base electrode. Here, we present an electrochemical yarn based on modified dry-spun reduced graphene oxide fibers. This braided format contains reference, counter electrode, a lactate-responsive fiber functionalized with lactate oxidase, and a pH-sensing fiber for calibration in a single, robust, weavable format. This electrochemical yarn was integrated into a demonstrator wearable textile-patch capable of continuous data collection and wireless data transmitted to an ad-hoc app. The yarns perform comparably to traditional probes in a format of broad utility for standalone or integrated monitoring of physiological parameters.

Iron Nanoparticle-Catalyzed Enantioselective Electro-Organic Carboxylation of Styrenes with CO2 Using Graphene Oxide Modified with PyrCO-cyclo@Fe in the Presence of Deep Eutectic Electrolyte and Solvent

Iron Nanoparticle-Catalyzed Enantioselective Electro-Organic Carboxylation of Styrenes with CO2 Using Graphene Oxide Modified with PyrCO-cyclo@Fe in the Presence of Deep Eutectic Electrolyte and Solvent

Kinetic Studies on MB Adsorption by Graphene like Material from Coconut Shell Charcoal

Coconut shell (CS) activated carbon is widely used for water purification, but its adsorption capacity is inferior compare to graphene oxide (GO). GO has oxygen functional groups so it can effectively bind pollutants like methylene blue (MB). In this study we synthesized graphene-like material from CS charcoal using the modified Hummers method by varying its oxidation times. The XRD decomposition results for H-CS3.2 show a structural composition similar to GO material. The diffraction peak at 10.7° (3.04%) falls within GO's characteristic range of 8°-11°, supported by a Raman ID/IG ratio of 0.95. In contrast, H-CS3.1 material does not exhibit GO's structural composition, with a diffraction peak at 13.9° (1.09%). An increasing of oxidation time, enhanced adsorption capacity in the equilibrium state of H-CS3.2 (22.368 mg/g) surpassing H-CS3.1 (17.079 mg/g). The heightened adsorption was linked to an increased O/C ratio or higher % of atomic oxygen (0.04 for H-CS3.1 and 0.17 for H-CS3.2). The pseudo second-order Ho (PSO) adsorption kinetic model demonstrated the adsorption mechanism, with active sites (oxygen functional groups) such as carbonyl (C = O) and epoxy (C – O) at basal plane carbon. Steric hindrance caused by hydroxyl functional groups (C – OH) led to a reduction in π-π interactions and decreased adsorption ability of the H-CS3.1 material. Desorption of H-CS3.1 material was influenced by MB detachment through interface diffusion.

Graphene Oxide-Enhanced Nucleation and Growth of Calcium-Silicate-Hydrate Gel at Nanoscale: A Molecular Dynamics Study.

Graphene oxide (GO) enhances the performance of cement-based materials by optimizing the microstructure of calcium-silicate-hydrate (C-S-H). However, the influence of GO on the nucleation and growth of C-S-H gel at nanoscale is unexplored. This study investigates this mechanism by molecular dynamics simulation at nano scale. Results show that GO can reduce the activation energy during the polymerization reaction of silicon oxide tetrahedra during the reaction process, and can increase the content of polymer Q3 and Q4. The influence of GO with epoxy (-O-), hydroxyl (-OH) and carboxyl (-COOH) groups on the radial distribution function (RDF), mean square displacement (MSD), and atomic spatial distribution of monomers are studied. Results show that GO-OH exhibits excellent performance, with the highest number of bridging oxygen atoms (about 0.6), the lowest Q0 monomer content (just 26.8%), the highest RDF (27.18), and the highest MSD (calcium and silicon content around 20,000 Å2). This paper elucidates the nucleation and growth mechanism of C-S-H influenced by GO to develop high performance cement.

Nanotechnology in Lithium-Sulfur Batteries: Addressing the Challenges in Battery Cycle Life and Safety

Lithium-sulfur (Li-S) batteries, with their high energy density and affordable material prices, are a viable alternative to ordinary lithium-ion batteries, especially for electric cars. Their actual application is limited by challenges such as substantial volume expansion, low electrical conductivity, and the polysulfide shuttle effect, despite their advantages. This research investigates how incorporating nanomaterials into Li-S battery cathodes, anodes, and electrolytes might improve battery performance and analyzes the potential of nanotechnology to address these problems. The application of metal oxides, graphene oxide, and carbon nanofibers to improve the stability and conductivity of sulfur cathodes is covered. Additionally, it examines anode protection strategies using nanocoating and protective layers to inhibit dendrite growth and improve safety. The incorporation of nanoparticles in electrolytes to improve ionic conductivity and reduce side reactions is also analyzed. Despite the progress, challenges such as the polysulfide shuttle effect and volume changes remain. The paper concludes with recommendations for future research to develop commercially viable Li-S batteries with higher capacity, longer lifespan, and improved safety.

Rapid and sensitive whole cell E. coli detection using deep eutectic solvents/graphene oxide/gold nanoparticles field-effect transistor

Every year, millions of people suffer from gastrointestinal inflammation caused by E. coli. The increase of antibiotic-resistant strains and similar inflammatory and infectious syndromes symptoms have made rapid and sensitive diagnosis of this pathogen challenging. This study developed a Field-Effect Transistor based on deep eutectic solvents, graphene oxide, and gold nanoparticles (DES/GO/AuNPs-FET) to detect E. coli. Comparing the output current showed DES, which was a mixture of ethylene glycol and choline chloride, with ionic behavior, in addition to improving the electrical properties of GO, also led to the formation of AuNPs by self-assembly, which significantly increased the sensor's sensing performance. E. coli lipopolysaccharide aptamer immobilized on DES/GO/AuNPs-FET; capturing E. coli and changing the conformation caused changes in the charge carrier flow in the FET. This nanobiosensor detected E. coli in a completely selective manner in complex matrices like human blood serum. The excellent sensing performance of this nanobiosensor compared to other biosensors with a low detection limit (LOD = 3 CFU/ml), label-free, fast, and real-time detection showed that DES/GO/AuNPs-FET could be a reliable alternative to existing detection methods.

Development of engineered Zn-MOF/g-C3N4 based photoelectrochemical system for real-time sensors and removal of naproxen in wastewater

Naproxen-contaminated water may lead to the accumulation of the drug in aquatic organisms and can pose high risks to an aquatic environment and human beings. Therefore, this work aimed to develop photoelectrochemical sensing and degradation of naproxen (NPX) using zinc-metal organic framework /graphitic carbon nitride thin film-based fluorine-doped tin oxide (Zn-MOF/g-C3N4/FTO) as anode material for the sensing and degradation of naproxen (NPX). The surface morphology, structure, surface property, surface area, optical property, photocurrent, and charge transfer kinetics abilities were studied using different techniques. The nanocomposites showed a superior photocurrent response (0.815 mA cm-2) compared to the original g-C3N4 (0.328 mA cm-2). The photo-anode made of Zn-MOF@g-C3N4/FTO displayed the highest photocurrent value, indicating that the alignment of the two semiconductor bands prevented the quick recombination of electron-hole pairs. Owing to these attractive features, the Zn-MOF/g-C3N4/FTO electrode was applied for photoelectrochemical detection of NPX using chronoamperometry. Interestingly, the nanocomposites-based FTO ascribed a lower detection limit (2.3 ng l-1) with a wide linear range concentration of NPX (0.5 to 200 µg l-1). Additionally, the analytical assessment of repeatability and reproducibility demonstrated robust performance, with commendable relative standard deviations (RSD%) of 2.54 % and 2.40 %, respectively. On the other hand, a remarkable degradation efficiency of 97.52 % was attained when employing a bias potential of 0.1 V during a 2 h photoelectrocatalytic oxidation of NPX. The degradation process was primarily driven by the active participation of holes and hydroxyl radicals in ring opening and subsequent cleavage of by-products. The notable effectiveness of this degradation can be attributed to the combined and synergistic effects of both electrochemical and photocatalytic degradation techniques. The current state demonstrates its effectiveness in the photoelectrochemical sensing and removal of NPX using MOF/g-C3N4 nanocomposites-based electrode materials in wastewater.

Ferroelectric Dipoles Tailoring Solid‐Electrolyte‐Interphase Chemistry to Enable Reversible Lithium Metal Batteries

AbstractSolid‐electrolyte interphase (SEI) plays a decisive role in building reliable Li metal batteries. However, the scarcity of anions in Helmholtz layer (HL) caused by electrostatic repulsion usually leads to the inferior SEI derived from solvents, resulting in dendrites and ‘dead’ Li. Therefore, regulating the distribution of anions in electric double layer (EDL) and continuously introducing more anions into HL to tailor anions‐derived SEI is crucial for achieving stable Li plating/stripping. Herein, by jointly utilizing the controlled defects of reduced graphene oxide (rGO) and the oriented dipoles of ferroelectric BaTiO3 (BTO), the rGO‐BTO composite layer sustainedly brings more TFSI− and NO3− into anion‐defecient HL, promoting favorable decomposition of anions and guiding the generation of robust and fast‐Li+‐transport SEI containing more inorganics LiF and Li3N species. Thus, the resulting Li deposit shows smooth and dense morphologies without dendrites, leading to high average Coulombic efficiency. The Li//Cu@rGO‐BTO (10 mAh cm−2 plated Li) cell exhibits an enhanced Li plating/stripping stability (2700 h) and a higher rate capability. The LiFePO4 full cell (N/P≈6.3) using rGO‐BTO displays an enhanced capacity retention (82.0 % @ 430 cycles). This work provides a new insight on the construction of robust SEI by regulating the distribution of anions within EDL.