Intercalated Graphene Oxide Research Articles

Polyvinylidene fluoride-based loose nanofiltration membrane with graphene oxide intercalation for efficient small organic molecules desalination

Graphene oxide (GO) loose nanofiltration (LNF) membranes show immense potential for the desalination of small organic molecules. However, it remains a significant challenge to compare the performance of GO LNF membranes prepared via different doping methods and study the mechanisms that influence the separation abilities of the membranes. In this study, LNF membranes prepared via three GO doping methods were examined for flux, retention rate, and the separation performance of small organic molecules and inorganic salts. The membranes coated with dopamine (DA) and GO, and subsequently formed polydopamine (PDA)–GO intercalation, showed the best results. A novel LNF membrane material (PVDF/PDA–GO–TFN; PVDF: polyvinylidene fluoride, TFN: thin-film nanocomposite) was developed to enhance the separation performance of small organic molecules and inorganic salts while improving membrane surface stabilization and anti-fouling performance and reducing the “trade-off” effect. The optimal conditions for PDA–GO intercalation and the best combination for interfacial polymerization (IP) were also determined. The intercalation structure was identified via scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and Fourier-transform infrared spectroscopy. Furthermore, the separation mechanism of the membrane was determined to be based on the Donnan and steric hindrance effects, according to the correlation analysis of the membrane surface electrical properties (zeta potential), hydrophilicity (contact angle), and pore properties. The PVDF/PDA–GO–TFN LNF membrane displayed a maximum water permeance of 10.45 L/(m2·h·bar), with an 88 % rejection of PEG2000 and a 6.83 % rejection of Na2SO4. Moreover, the membrane exhibited excellent anti-fouling performance and long-term stability, with a mean flux recovery rate of 99.06 % after four cycles of filtration and backwashing tests using small organic molecules and inorganic salt solutions. The inorganic salt retention rate was analyzed using SPSS software, and the results indicated excellent membrane stability. In summary, the preparation of PVDF/PDA–GO–TFN membrane materials provides a novel approach for fabricating LNF membranes that can effectively separate small organic molecules and inorganic salts.

Carrier-driving CO2 separation by amine-rich membranes with intercalated graphene oxide

Amine-rich facilitated transport membranes (FTMs) attract great interest in intensifying the membrane-based CO2 separation processes. The high-molecular-weight polyvinylamine (PVAm) polymers containing fixed-site carriers of the amino groups were used to prepare highly CO2-permeable membranes. The sterically hindered PVAm polymers of poly(N-methyl-N-vinylamine) and poly(N-isopropyl-N-vinylamine) were obtained by functionalization of PVAm to provide superior CO2 solubility. By loading the mobile carriers of amino acid salt (AAS) and CO2-philic graphene oxide (GO), the prepared FTMs render enhanced CO2 permeance and CO2/N2 selectivity. The d-spacing of 8.8 Å and the ultramicropores of 3.5 Å from GO nanosheets provide the combination of both selective surface flow and molecular sieving mechanisms to achieve improved CO2 permeance and CO2/N2 selectivity. In addition, the intercalation of GO hinders N2 transport through the membrane due to a longer pathway, while the mobile carriers of AAS introduced into the PVAm matrix facilitate CO2 transport through the selective layer. Therefore, the CO2/N2 selectivity of the prepared FTMs was significantly enhanced to 171 based on the intensified carrier-driving transport mechanism. It can be concluded that amine-rich membranes based on both fixed and mobile carriers of the amino groups together with intercalated GO can synergistically improve the CO2/N2 separation performance, and be potentially applied for CO2 capture from flue gas.

Robust construction of polyvinyl alcohol intercalated graphene oxide nanofiltration membrane for desalination via pervaporation

The construction and modification of a Graphene Oxide (GO) membrane, incorporating polyvinyl alcohol (PVA) cross-linked with maleic acid (MA) and supported by a nylon membrane, have been successfully completed. Systematic variations in PVA and MA concentrations were conducted to achieve membranes with favorable characteristics, stability, and excellent desalination performance. Optimization studies utilizing the Central Composite Design (CCD) revealed that the most optimal desalination results were obtained with 10 mL of PVA (0.1 mg mL−1) and 0.9 M of MA (GO-MA0.9-PVA10/Nylon membrane). Experimental findings demonstrated that the inclusion of PVA and MA resulted in an increased interlayer distance of GO and enhanced membrane stability. The addition of PVA increases GO membrane hydrophilicity, while the addition of MA reduces membrane hydrophilicity. The GO-MA0.9-PVA10/Nylon membrane exhibited the highest desalination performance, boasting a rejection value exceeding >99.9% and a permeance of 18.76 kg m−2.h−1 under 1% NaCl feed at a temperature of 50 °C. This membrane demonstrated consistent desalination performance stability over an extended period of up to 70 h. Moreover, it exhibited durability through 8 cycles of 24-h usage with washing treatment. In conclusion, the GO-MA0.9-PVA10/Nylon membrane is strongly recommended for practical applications, outperforming other membrane options based on the comprehensive evaluation of its stability and desalination efficiency.

Montmorillonite-Silica-Graphene oxide composite incorporating with chiral thiourea for the Strecker reaction

The present study has successfully intercalated graphene oxide (GO) nanosheets and silica into the montmorillonite (MMT) interlayer and deposited them onto its external surface to make montmorillonite, silica, and graphene oxide composite (MMT-silica-GO). The as-prepared composite demonstrates improved thermal stability compared to neat MMT and GO. It was followed by incorporating chiral thiourea (CTU) scaffold into MMT-silica-GO-based composite to establish chiral MMT-silica-GO-CTU-based heterogeneous system and tested over Strecker reaction, revealing high activity and selectivity. FTIR, Raman spectroscopy, powder X-ray diffraction, SAXS, XPS, BET, SEM, EDAX, and thermogravimetric analysis were used to characterize the samples. It was credited to the synergistic effect between the composite components that enhanced access to active sites and dispersion of catalyst. Across the board, the chiral MMT-silica-GO-CTU-based heterogeneous system appears to be a promising candidate for the Strecker reaction.

Highly selective ion transport by freestanding Zn-Imidazole complex intercalated graphene oxide membrane for enhanced blue energy harvesting

Generating electricity from seawater by utilizing nanofluidic structures is an appealing strategy for achieving zero-emission energy goals. A nanofluidic channel that is atomically small, tunable, and mechanically stable is the key to solving this problem. In this paper, for the first time, we report the construction of centimeter-sized freestanding zinc-imidazole complex (ZnIm) intercalated graphene oxide (GO) membrane (GO-ZnIm) having uniform 2D nanofluidic channels with interlayer spacing of 9 Å. The pristine GO membrane rapidly disintegrates in an aqueous medium due to membrane swelling; however, treatment with an aqueous zeolitic imidazole framework (ZIF-8) suspension, rendering ZnIm complex, provides long-term stability by restricting the excessive interlayer separation of GO sheets. From ion transport, diffusion, and variable load studies, it is observed that, besides stabilizing the GO membrane, intercalation of ZnIm significantly improves average cation selectivity (from 0.46 for GO to 0.74 for GO-ZnIm, measured up to 1000 concentration gradient) and experimental power density (from 1.7 Wm−2 for GO to 10.8 Wm−2 for GO-ZnIm, at 1000 concentration gradient). Moreover, the practical applicability of the GO-ZnIm membrane has also been investigated under artificial estuary conditions at ambient temperature, rendering an osmotic power density of 4.5 Wm−2, which is very close to the commercial benchmark of 5 Wm−2. A mechanically robust and flexible membrane made up of cost-effective components (GO and ZnIm), able to deliver an osmotic power density close to commercial benchmark at ambient temperature is the main highlight of the present GO-ZnIm membrane, which can be a promising candidate for applications such as separation, desalination, and blue energy harvesting.

Self‐assembly of thiourea intercalated graphene oxide based dual IIP for the SPE coupled FAAS method development of Cu(II) and Pb(II) determination

AbstractA new dual‐template surface imprinted polymer for Cu(II) and Pb(II) was synthesized in one pot. Magnetic graphene oxide was self‐assembled with low cost and environmentally benign thiourea. Presence of sulfur and nitrogen donor atoms provide hooks for coordination and partial reduction of graphene oxide matrix. It was used as an solid‐phase extraction adsorbent for extraction, preconcentration, and coupled with flame atomic absorption spectrometry to manifest performance comparable with inductively coupled plasma atomic emission spectrometry (ICPAES) both in terms of quantification limit as well as interference. The critical experimental parameters such as pH; 4.6, contact time of 15 min and initial concentration of 777 (Qe; 227 mg g−1) and 800 μg L−1 (Qe; 273 mg g−1) for Cu(II) and Pb(II), respectively, were optimized using RSM‐CCD and artificial neural network. The adsorption process was kinetically faster (50% adsorption in 5 min), following fractal‐like‐pseudo‐second‐order (FLPSO) kinetics and Brouers–Sotolongo isotherm model owing to the heterogenous energy landscape. The imprinting factors were in the range of 4–7 in the presence of all coexisting ions. The proposed method was robust in the determination and removal of Cu(II) and Pb(II) from food, ground water, and industry effluents with low limit of detection (Cu(II); 1.03 μg L−1 & Pb(II); 1.79 μgL−1). Spiking and recovery tests were used to assess the method's accuracy. Cu(II)/Pb(II) loaded dual template IIP (DIIP) was utilized to remove anionic dyes with >95% efficiency. Thorough examination of the method and material selectivity (in binary, ternary, and multielement system), multi fold applications of determination, removal of Cu(II), Pb(II), and removal of anionic dyes makes DIIP a promising candidate for environmental remediation.

Crown ether intercalated graphene oxide membranes for highly efficient sieving of cesium with a large water permeability

The highly efficient sieving of Cs+ from natural brine resources has garnered considerable attention for the extraction of cesium raw materials. However, for the trade-off between ion rejection and water permeability, it remains challenging for graphene oxide (GO) membranes to improve efficient sieving of Cs+ with a large water permeance. Here, we have successfully addressed this challenge by fabricating a GO membrane that incorporates crown ether (CE) through π-π and CH-π interactions with GO sheets. This CE intercalation has resulted in a significantly enhanced Cs+ sieving capability from salt lake brines, concurrently improving water permeance. The unique Cs+ selective cavity structure of the CE has enabled the GO membrane to exhibit a Cs+ rejection rate of 94.4 % and a water permeance of 15.8 L m−2 h−1 bar−1 at a Cs+ concentration of 0.150 mmol/L (∼20 ppm). Compared to the pure GO membrane, these results represent an improvement of over 70 % in Cs+ rejection and more than 230 % in water permeance. Interestingly, we have also observed that this GO membrane exhibits a low Na+ system consisting of two components, the separation factor of Cs+/Na+ reaches up to 5.0, which is significant in monovalent ionic membrane separations. These significant discoveries provide a promising strategy for the highly efficient extraction and concentration detection of Cs+ from complex ion solutions.

Evolution of structural features in GO/CdS multilayer films for advanced optoelectronic devices

In this work graphene oxide/cadmium sulphide [GO/CdS]n multilayer films were obtained onto FTO/SLG substrates by cyclic electrophoretic deposition (EPD) and successive ion layer adsorption and reaction (SILAR) methods, with 3, 5, 7 and 10 cycles. The optical characterization for 3 cycles sample exhibits an optical band gap of ∼2.9 eV due the nanocrystalline nature of CdS, from 5 to 10 cycles a blue shift is observed in the band gap around ∼2.15 eV by the electronic disorder induced by graphene oxide intercalation and the mixture of hexagonal/cubic phases of CdS. Raman spectra shows the longitudinal optical modes LO, 2LO and 3LO, the LO peak position shows a blue shift in comparison to the bulk CdS. The multilayer films of 3 and 5 cycles shows a wide range of photoluminescence emission from 350 to 700 eV, for samples of 7 and 10 cycles a quenching and red shift is observed attributed to the CdS crystals growth with a peak emission at 615 eV from bulk CdS, which make the materials suitable for photovoltaic solar cells and UV-Vis diodes for optoelectronic devices.

Dielectric response of alkali aluminosilicate hydrate and silico alumino phosphate network present in metakaolin–graphene oxide geopolymer: A comparative study

Metakaolin-based geopolymeric composites are regarded as potentially useful materials for a number of applications because of the strength of networks present in them. In the present study, the binding network of aluminosilicate hydrate or silico alumino phosphate network of metakaolin is activated using sodium silicate (MA) and phosphoric acid (MP), respectively, and reinforced with an optimised dose of graphene oxide (GO) for dielectric applications. The sheet-like structure of graphene oxide present in the network was confirmed by transmission electron microscopic (TEM) analysis and the selected area diffraction (SAD) pattern showed relatively diffuse scattering spots. The alignment in the growth of N-A-S-H and S-A-P gels with fibrillar products at various points on the GO surface was observed in scanning electron microscopic (SEM) images. The reinforcement with GO improves the compressive strength of both types of geopolymers (G-MA, G-MP) by 20 % compared to that of control specimens (MA, MP). This could be due to the acceleration of the reaction with a higher amount of N-A-S-H gel in MA and a synergistic formation of silicoalumino phosphate and aluminium phosphate in MP. GO intercalation was confirmed from the intense peaks of D band of GO at 1300–1450 cm−1 in the Raman spectrum in MA and MP as well as different Q1–4Si environments pertaining to the geopolymeric network. The impedance spectroscopy was used to investigate electrochemical properties like static high-frequency dielectric permittivity, suppressed electrical conductivity, reduced loss tangent, increased resistivity and modulus. Dielectric constant (K) calculated for was found to be in the order G-MP < G-MA < MP < MA with the corresponding values of 1.17 < 1.26 < 1.78 < 2.68 × 1013. Free cation (Na+) transference under the influence of an electric field in alkali-based geopolymer is more pronounced than in phosphate-based composites. This study provides a new insight into the design of metakaolin nanocomposites as an alternative to solid oxide fuel cell/fast inorganic ionic conductors as well for insulation packaging.

Highly Efficient Arginine Intercalated Graphene Oxide Composite Membranes for Water Desalination.

Graphene oxide-based composite membranes have received enormous attention for highly efficient water desalination. Herein, we prepare arginine/graphene oxide (Arg/GO) composite membranes by surface functionalizing GO nanosheets with arginine amino acid. Arginine has a unique combination of hydroxyl and amino functional groups that cross-link GO nanosheets through hydrogen bonding and electrostatic interactions. The as-prepared Arg@GO composite membranes with different thicknesses are used to separate the salt and dye molecules. The 900-nm-thick Arg@GO composite membrane shows high rejection of 98% for NaCl and 99.8% for MgCl2, Ni(NO3)2, and Pb(NO3)2 with good water permeance. Such a membrane also shows a high separation efficiency (100%) for methylene blue, rhodamine B, and Evans blue dyes. At the same time, the ultrathin Arg@GO composite membrane (220 ± 10 nm) exhibits high water permeance of up to 2100 ± 10 L m-2 h-1 bar-1. Furthermore, the 900-nm-thick Arg@GO composite membrane is stable in an aqueous environment for 40 days with significantly less swelling. Therefore, these membranes can be utilized in future desalination and separation applications.

Synthesis and characterization of MgAl- layered double hydroxide with graphene oxide intercalation: Application in lead removal from spent batteries effluent

New-energy batteries are being developed so quickly leaving behind a challenge of lead contamination from spent batteries. Many adsorbents were developed to eliminate lead from the wastewater, layered double hydroxide (LDH) is one of them. A super adsorbent Graphene Oxide (GO) intercalated MgAl-LDH (GO-LDH) was specially designed and synthesized as effective and selective lead adsorption. The GO-LDH was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM). XRD result shows an increase in d-spacing corresponding to the (003) plane of LDH. A disappearance of the COOH group stretching in the FTIR spectrum of GO-LDH was observed in the FTIR spectrum. These results confirm the intercalation of GO between the basal plane of MgAl-LDH. To fit the adsorption isotherm, the Langmuir model was utilised, yielding pseudo-second-order rate kinetics with a maximum sorption capacity of 1034 mg/g at 50 °C and pH 6.0. These findings conclude that GO-LDH could be a promising application to treat heavy metal-containing wastewater with selective adsorption of lead.

Label-free immunosensor based on a one-step CTAB intercalated graphene nanocomposite for hepatitis C virus detection

A new label-free immunosensor containing cetyltrimethylammonium bromide (CTAB) intercalated-graphene oxide (GO) on a polythiophene (PTh) film one-step electrosynthetized is described for detection of hepatitis C antibodies (Anti-HCV). This electroactive film also acted as a substrate for immobilizing the biorecognition element. The ability of the biosensor to bind Anti-HCV was monitored by the square wave voltammetry (SWV) technique through the decrease in anodic peaks. The intercalation of GO nanosheets between CTAB and PTh was very stable, achieving a variation coefficient of approximately 0.65% for redox peaks after 30 cycles, and was also demonstrated as a diffusion-controlled process with excellent electrochemical reversibility. The immunosensor exhibited a linear response range from 0.2 to 8 ng∙mL−1, good reproducibility (square R equal to 0.993, low relative error < 1%), and a limit of detection at 0.07 ng∙mL−1 of Anti-HCV, achieving the clinical range for HCV diagnostic. Furthermore, this approach shows promise for constructing a practical and accurate immunosensor for HCV diagnostic and screening in chronic phases and monitoring other HCV biomarkers utilizing this technology.

Cu ions intercalated GO/Cu2O photocathode-enabled promotion on charge separation and transfer for efficient photoelectrochemical water splitting

The development of cuprous oxide (Cu2O) photocathode for photoelectrochemical (PEC) water splitting confronts charge recombination and photocorrosion. Herein, a facile strategy for wrapping Cu2O photocathode with Cu ions intercalated graphene oxide (Cu-GO) was proposed to realize efficient PEC water splitting. The intercalating GO with Cu ions could reduce the bandgap and enhance the carrier mobility of Cu-GO. The as-formed Cu-GO could suppress surface charge recombination and accumulation of the Cu-GO/Cu2O photocathode by improving the interfacial charge transfer, which strengthens electron extraction and restrains photocorrosion. The Cu-GO/Cu2O photocathode achieved a high photocurrent density of − 7.03 mA cm−2 (at 0 V vs. RHE) under AM 1.5 G illumination and excellent photostability for PEC water splitting. This work provides a simple way to design Cu2O-based photocathodes with reliable charge transfer layers for efficient PEC water splitting.

Tailoring the microstructure of silver nanoparticle-intercalated graphene oxide membranes for desalination by pervaporation: Water permeation, membrane fouling, and antibacterial property

Low water flux has limited pervaporation (PV) from being applied in industrial-scale desalination. In this work, membranes embedded with silver nanoparticles (Ag NPs)-intercalated graphene oxide (GO) are proposed and prepared through two methods (self-assembly and blend) to improve membrane water permeation and fouling resistance. The Cs/Ag NP/GO@BM exhibited superior water permeation among the prepared membranes for the following reasons: 1) Water adsorption was improved by both the surface and interlamellar space of the blended matrix; 2) The intercalation effect of Ag NPs and looser stacking structure created more favorable diffusion pathways for water transportation. In the brine fouling test, the water flux of the membrane declined, while the fouling was reversible by NaOH cleaning with a high flux recovery rate (>97 %). Additionally, the Cs/Ag NP/GO@BM exhibited a remarkable antibacterial rate of 99.6 % against E. coli, benefiting from the synergistic inhibiting effect of GO and Ag NPs.

Molecular intercalated graphene oxide with finely controllable interlayer spacing for fast dye separation

Molecular intercalation has been widely used for graphene oxide (GO) nanosheets to control interlayer spacing (d-spacing). However, further research is necessary to refine and enhance the precision of d-spacing control. In this study, we demonstrate a versatile strategy to create chitosan (CS) intercalated GO (GO@CS) nanosheets, whose d-spacing can be finely controlled by numbers of linked CS unit. This means the concentration of CS solution directly influences d-spacing of GO, and we can get the desired d-spacing for various applications by modulating the CS concentration. This is benefited from the linear structure of CS ensuring a consistent molecular length. The simulation of molecular structures with different numbers of linked CS unit supports this model. Then, the nanofiltration membranes prepared by these GO@CS nanosheets show high hydrophilicity, strong chemical bonding force, and abundant negative charges, which enhances permeability (water permeance of 91 L m−2 h−1 bar−1), stability, and anti-fouling ability during dye separation processes, even though they are ultrathin (∼70 nm). Notably, the contrasting filtration efficiencies observed for oppositely charged dye molecules indicate a great potential use in molecular sieving.

Fabrication of negatively charged nanofiltration membrane of modified polystyrene intercalated graphene oxide for pervaporation desalination

Polystyrene intercalated graphene oxide (GO) membranes with and without sulfonation were successfully prepared for pervaporation desalination applications. The membrane was deposited on nylon support and linked with Zn2+ (c) as a crosslinker. To improve membrane performance, modification of polystyrene via sulfonation was also carried out to convert polystyrene (PS) into polystyrene sulfonic acid (PSSA). The interlayer spacing (d-spacing), hydrophilicity, and stability were observed as the membrane characteristics which greatly influenced the desalination performance. Experimental results show that intercalation of GO with PS and PSSA increases the interlayer spacing and membrane stability. The addition of PS decreased the hydrophilicity of the membrane, while the addition of PSSA increased the hydrophilicity. Calculations for optimizing desalination using Central Composite Design (CCD) on c-PSSA-GO/Nylon membranes show that the optimum temperature and time can be achieved at 57 °C and 71 min. The c-PSSA-GO/Nylon membrane showed the best results with a NaCl rejection value of > 99% and a water flux of 15.56 ± 0.6 kg m-2h−1, which was applied to 1% NaCl feed. The c-PSSA-GO/Nylon membrane also shows consistent NaCl rejection and water flux when applied for an extended period. So, the c-PSSA-GO/Nylon membrane has excellent potential for pervaporation desalination.

Phosphorus‐containing hyperbranched polysiloxanes intercalated graphene oxide and their flame retardant effect on epoxy resin

AbstractIntrinsic flammability significantly impedes practical applications of epoxy (EP), despite many merits. Intercalation‐functionalized graphene oxide (GO) has shown excellent performance in flame retardancy studies of polymers, but research investigating the effect of layer spacing on the flame‐retardant performance of polymers is still lacking so far. Therefore, three GO flame retardants with different layer spacing were prepared to flame retardant EP. When the layer spacing of GO is 1.09 nm, the heat and smoke release from EP composites is effectively suppressed. This is attributed to the barrier effect and maze effect of GO as well as the synergistic effect between the intercalator and GO. Analysis shows that the layer spacing of GO affects the flame retardancy of the composite by influencing the formation of protective char layer.

A g-C3N4/Fe-MOF heterojunction intercalated graphene oxide membrane with persulfate activation self-cleaning property for efficient crude oil in water emulsion separation

Developing the membrane with splendid anti-fouling ability is urgently desired for the separation of high-viscosity crude oils emulsions. Herein, a novel GO-based membrane with anti-crude oil fouling and persulfate activation self-cleaning properties was fabricated by introducing g-C3N4/NH2-MIL-88B(Fe) (g-C3N4/NMB) heterojunction into graphene oxide (GO) sheets via a sample self-assembling process. Combing with micro-nano structures and hydrophilic properties of g-C3N4/NMB heterojunction, GO@g-C3N4/NMB membrane exhibited resplendently selective wettability and anti-crude oil adhesion performance. Based on this, the resultant membrane effectively realized the separation to different low-viscosity oily wastewaters (all rejections >98%). Facing high-viscidity crude oil emulsions, the permeate flux could reach 1611 ± 63 L m-2 h-1 bar-1 with 99.21% of reject rate, which increased almost 80 times than GO membranes. Moreover, profiting from the distinguished photocatalytic activity of g-C3N4/NMB and electron transport capacity of GO nanosheet, the catalytic degradation rate of GO@g-C3N4/NMB membrane was enhanced over 5 times compared to GO membrane under visible light radiation, reaching 0.1513 min-1 for MB under 0.6 mM peroxydisulfate (PDS). Hence, GO@g-C3N4/NMB membrane could reveal continuous purification of organic wastewater through the synergistic effect of filtration and photocatalysis. Similarly, the crude oil-fouled membrane also accomplished regeneration after 30 min of light irradiation and the Rir of GO@g-C3N4/NMB-3 membrane decreased to only 3.7% by persulfate activation self-cleaning strategy. Therefore, this work provided a beneficial avenue for developing sustainable, renewable separation membranes of crude oil emulsions.

Organic-inorganic building block of phytic acid intercalated graphene oxide for performance enhancement of plant-derived adhesives

The introduction of 2D graphene into the soybean protein (SP) adhesive is expected to enhance its mechanical performance. However, insufficient binding of the two materials inevitably leads to the resulting composite having limited mechanical strength. Using phytic acid (PA) and a supramolecular self-assembly strategy, hard graphene oxide (GO) was first assembled with PA to form a supramolecular polymer, PA-co-GO, that has a “bricks and mortar” structure as a result of strong non-covalent interactions. PA-co-GO was then further combined with SP in the presence of the long-chain epoxy compound neopentyl glycol diglycidyl ether (NG) to produce a novel biopolymer-based adhesive PA-co-GO/NG/SP. The prepared adhesive has a moisture-insensitive interface as a result of non-covalent/covalent bonds and a “bricks and mortar” microstructure that allows the dissipation of energy, resulting in an enhancement in the water-resistant bonding strength of the material, with a 345% increase in its wet bonding strength compared with the unmodified SP adhesive. Additionally, the combination of the heat shielding of the GO and catalytic carbonization of PA resulted in the adhesive having excellent flame retardant properties. The structure and morphology of the materials were characterized using atomic force microscopy (AFM), dynamic light scattering (DLS), Fourier-transform infrared (FTIR), X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and solid-state 13C NMR. Overall, a new clean route for preparing green high-performance biopolymer-based adhesives is described, with potential applications for sustainable agricultural byproducts.

Electrochemical exfoliation and deposition of sodium-graphene oxide composite for high specific capacity cathode/anode for dual-carbon sodium ion battery application

We provide information on a straightforward process for creating sodium-carbon-based material for Na-ion batteries. The electric-controlled exfoliation method produced sodium intercalated graphene oxide (Na-GO). Na-GO has a crystalline structure with a few-layered scattered sheet shape, 87.9 percent crystallinity, a computed density of 2.26 g/cm3, and a cell volume of 35.29x106pm3. The Coulombic efficiency of the Na-GO material increased from 98.8% in the first electrochemical cycle to 100.5 percent in the 60th, and the specific capacity (S.C.) of the Na-GO electrode at a current density of 100 mA/g is about 368 mAh/g. Galvanostatic charge–discharge cycles against sodium metal were carried out as a reference electrode. This is a brand-new method for creating high-performing materials that do not require purifying or cleaning procedures.