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Organic-inorganic hybrid nanocomposites are rapidly evolving as a new generation of materials with attractive properties for electrochemical energy storage. Unfortunately, their practical applications in sodium-ion batteries (SIBs) still require further research due to the unsatisfactory cycling stability and rate performance. This work explores using zinc antimony oxide/reduced graphene oxide (ZSO/rGO) hybrid nanocomposite as an anode material in SIBs. After 150 cycles at 0.05 A g−1, the ZSO/rGO electrode delivers a specific capacity of 357.21 mAh g−1 with a coulombic efficiency of 99.3 %, which is almost 2.5-fold higher than the specific capacity of the pristine ZSO electrode. An in-situ Raman spectroscopy study demonstrates that the sodiation/desodiation mechanism in the ZSO/rGO electrode involves the conversion and alloying reactions in the ZSO nanoparticles. Further electrochemistry analysis reveals that the nanocomposite anode shows synergistic effects by coupling diffusion and surface contribution, in which the latter plays an important role. [ABSTRACT FROM AUTHOR]

Hybrid membranes combining graphene oxide (GO) and silicon dioxide (SiO 2) were successfully developed for pervaporation desalination using porous zircon tube substrates. These GO/SiO 2 membranes were carefully designed by adjusting the amount of GO and the pH levels during the dip-coating process on the zircon tube surface. The study aimed to investigate how varying amounts of GO and pH levels affect the membranes' properties and desalination performance. The results indicate that raising the pH level decreases the membranes' hydrophilicity and enhances their stability. Conversely, increasing the amount of GO increases the membranes' hydrophilicity and reduces their pore size. Higher pH levels and GO amounts resulted in better salt rejection but lower water flux. Among the tested membranes, GS-6 (0.3 % GO/SiO 2 , pH 6) achieved the highest salt rejection rate of 99.96 % at 30 °C with a 1 % NaCl feed concentration. In contrast, GS-1 (0.1 % GO/SiO 2 , pH 4) showed the highest water flux of 8.54 kg m−2 h−1 at 60 °C with the same feed concentration. Increasing the temperature led to decreased salt rejection but increased water flux. Additionally, higher feed concentrations lowered both salt rejection and water flux. [ABSTRACT FROM AUTHOR]

This study introduces a cost-effective and eco-efficient method for fabricating an advanced microwave absorber using a layer-by-layer rGO and SiO 2 structure. The rGO/SiO 2 composite, synthesized via modified Hummer's and Stöber methods, demonstrates remarkable microwave absorption properties. The resultant porous structure, characterized by an S BET of 294.89 m2/g, enables multiple reflections and scatterings of electromagnetic waves. At a sample thickness of 3.8 mm, the material achieves a reflection loss (RL) of −47.43 dB at 12.56 GHz and an effective absorption bandwidth (EAB) of 11.04 GHz. For a 6 mm thick sample, an exceptionally high EAB of 12.72 GHz is observed, maintaining a high RL of −42.32 dB. These results demonstrate that the rGO/SiO 2 material is a promising candidate for applications in electromagnetic wave absorption, offering a simple, scalable solution for mitigating electromagnetic pollution and enhancing military stealth technologies. [ABSTRACT FROM AUTHOR]

In recent times, there has been a pressing need to discover or manufacture a unique material that can serve as a photocatalyst for organic pollutants that are incapable of degradation. Pure Bi 2 O 3 and Co, Cd co-doped Bi 2 - 2x Co x Cd x O 3 (x = 0.8) nanoparticles were synthesized using the chemical co-precipitation method, but the new approach involves fabricating 10 % reduced graphene oxide Bi 2 - 2x Co x Cd x O 3 /rGO nanocomposites via the ultra-sonication route. This study investigated the effects of Co, Cd, and r-GO doping on the optical, electrochemical, structural, and photocatalytic properties of bismuth oxide. The synthesized nanomaterials were analyzed using X-ray diffraction (XRD), cyclic voltammetry, ultraviolet–visible (UV–Vis), Fourier transform infrared (FTIR), photoluminescence (PL), and Raman spectroscopy. The XRD patterns showed the formation of a monophasic monoclinic structure belonging to space group P21/c, with an average crystallite size estimated around 22–41 nm. According to the UV–visible study, the bandgap energy of Bi 2 O 3 NPs, Bi 2 - 2x Co x Cd x O 3 NPs, and Bi 2 - 2x Co x Cd x O 3 /rGO nanocomposites were 2.64 eV, 2.37 eV and 2.06eV respectively. The cyclic voltammetry technique was used to evaluate the functioning electrodes. In contrast to un-doped Bi 2 O 3 , the synergistic effects of Co, Cd, and r-GO on the substituted material increased the specific capacitance. The pure Bi 2 O 3 , doped Bi 2 - 2x Co x Cd x O 3, and Bi 2 - 2x Co x Cd x O 3 /rGO photocatalyst degraded 62 %, 85 %, and 95.4 % respectively of RB-5 dye after 105 min of sunlight. The phytotoxicity analysis examined the germination of Hordeum vulgare seeds in treated and untreated RB-5 dyes. Additionally, scavenging investigations using reactive species trapping to confirm the dominant reactive species were evaluated. Bi 2 - 2x Co x Cd x O 3 /rGO nanocomposites are better at photocatalysis and have a narrow bandgap, which makes them useful as solar-active photocatalysts for getting rid of dyes in wastewater. In future, their composites with conducting polymers may improve their electrochemical and photocatalytic behaviour as well. [ABSTRACT FROM AUTHOR]

Developing sustainable and highly effective electrocatalysts for the oxygen evolution reaction (OER) is a significant research target for precise custody of water splitting to fulfill worldwide energy demands. This study focuses on the fabrication of SrTiO 3 /rGO-based composite via a solvothermal technique, which works as an electrocatalyst for evaluating the efficiency of OER in alkaline media. The material displays outstanding OER efficacy in 1 M KOH solution with its cubic structure validated by the X-ray diffraction (XRD) study. The electrochemical study reveals that the SrTiO 3 /rGO composite has a minimal overpotential (222 mV) compared to SrTiO 3 (289 mV) and the commercial catalyst RuO 2 (367 mV). The SrTiO 3 /rGO composite also has a minimal Tafel plot gradient of 37 mV dec−1 whereas RuO 2 has a Tafel value of 72 mV dec−1. The current material has superior properties compared to RuO 2 , a commercial catalyst for the OER. The SrTiO 3 /rGO composite shows exceptional stability for 40 h. The low conductivity of oxygen-deficient SrTiO 3 perovskite can be improved by incorporating carbon-based rGO into it, as demonstrated by the minimal Rct (0.07 Ω) obtained from electrochemical impedance spectroscopy (EIS) analysis and an enlarged surface area of 250 cm2, as evidenced by electrochemical surface area (ECSA). Therefore, our research indicates that a particular morphology of metal oxide can improve the efficiency of electrocatalysis when combined with reduced graphene oxide (rGO), suggesting its potential for generating effective and environmentally friendly energy. Hence, these findings may improve the smooth passage of electrons and provide a novel perspective to function as an adequate substitute for RuO 2 , a commercial catalyst. [ABSTRACT FROM AUTHOR]

Efficient 2D-inorganic spinel perovskites nanostructure materials are used as potential candidates for highly sensitive detection of harmful substances present in the environment. In this regard, a facile one-pot hydrothermal synthesis was employed to fabricate nanocomposite material containing iron manganese oxide (FeMn 2 O 4) decorated with reduced graphene oxide (rGO) which is used as an electrochemical detection of metronidazole (MTZ). The crystalline nature and structural insights of the as-synthesized FeMn 2 O 4 -rGO nanocomposite were established using various spectroscopic and electrochemical techniques. Distinctively FeMn 2 O 4 -rGO nanocomposite fashioned glassy carbon electrode (GCE) showed excellent linear range (0.01–512.2 μM), sensitivity (71.4 μA mM−1 cm−2), limit of detection (0.0129 μM), reproducibility, stability and resist-interference capability towards metronidazole (MTZ) antibiotic drug. In addition, the fabricated FeMn 2 O 4 -rGO/GCE electrochemical sensor exhibited a remarkable MTZ detection in spiked water as well as urine samples with better recovery percentages supporting its facile and feasible nature for environmental applications. The present work established the fabrication of FeMn 2 O 4 -rGO/GCE nanocomposite for effective determination of antibiotic drugs in real sample analysis. [ABSTRACT FROM AUTHOR]

We report a low cost, simple method to fabricate reduced graphene oxide (rGO) optical sensors from recycled batteries. The rGO nanosheets were exfoliated by electrochemical method under the assistant of electric arc using 5 % KOH or NaOH electrolytes. The rGO nanosheets show interlayer distances ranging from 3.98 to 6.22 Å, and thicknesses from 0.62 to 6.00 nm, corresponding from 1 to 10 layers, respectively, determined from X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM) measurements. Selected area electron diffraction (SAED) measurement indicates that rGO nanosheets content Miller-Bravais indices of (1–210) and (0–110) planes, and the hexagonal diffraction pattern of (0–110) plane of graphene sheets with d-spacing of 2.13 Å. Low defect densities in exfoliated rGO nanosheets were confirmed by I D /I G ratios ∼0.16 to 0.18 via Raman. The rGO nanosheets exfoliated in NaOH electrolyte have 19.35 % lower oxygen content compared to those exfoliated in KOH electrolyte inspected from XPS spectra. The performance of the rGO optical sensors is controlled by defects created from oxygen functional groups formed during exfoliation process. The responsivity and response (rise) time of NaOH-exfoliated rGO sensor are 0.46 A/W and 2.3 s, respectively. These values are 21 % (for responsivity) larger and 35 % (for rise time) smaller than those of KOH-exfoliated rGO sensor. The best-in-class of high gain were demonstrated in this study for the rGO optical sensors prepared from disposed graphite rods. The results demonstrate how disposed batteries can be recycled to produce photodetectors and other optoelectronic devices using cheap and relatively nontoxic methods. [ABSTRACT FROM AUTHOR]

Methamphetamine, pseudoephedrine, and related drugs are among the first drugs used for the stimulation of the central nervous system. In this study, two adsorbents based on graphene oxide (GO) were synthesized and used for the analysis of methamphetamine and pseudoephedrine. The prepared nano-adsorbents based on GO in this study were coated by polyaniline (PANI) and Fe3O4/C-nanodot/GO (magnetic adsorbent). The average size of nanoparticles (GO/PANI) was 18.43 nm. The specific surface area and pore size diameter of Fe3O4/C-nanodot/GO were 22.71 m2 g− 1 and 15.23 nm, respectively. Experimental variables affecting the extraction efficiency of the analytes such as pH of the sample solution, amount of adsorbent, extraction time, and type of eluents were investigated and optimized by response surface methodology. Under optimum conditions, GO/PANI and Fe3O4/C-nanodot/GO were considered appropriate solid phase extraction adsorbents for HPLC-based analyses of the studied drugs in human urine samples. However, GO/Fe3O4 nano adsorbent (Fe3O4/C-nanodot/GO) showed superior working condition than GO/PANI. The validated proposed analytical methods can be used for the quantitative determination of methamphetamine and pseudoephedrine in actual samples. [ABSTRACT FROM AUTHOR]

Graphene oxide-based nanomaterials are garnering significant attention from various fields due to their unique physical and chemical properties, which make them attractive for myriad applications. This feature article stems from Dr. Aicheng Chen's Lecture for the 2023 Ricardo Aroca Award of the Canadian Society for Chemistry and focuses primarily on the synthesis and applications of graphene oxide-based nanomaterials for electrochemical sensing. Graphene oxide (GO), reduced graphene oxide, and functionalized and doped GO-based nanomaterials are emerging as promising enablers of broad applications in electrochemical sensors. This is due to their distinctive functional groups and novel properties, which include high electrical conductivities, large surface areas, and enhanced catalytic activities. Several strategies for the synthesis of these nanomaterials are described in this feature article, encompassing the modified Hummers method, electrochemical, thermal, and microwave reactor methods. The characterization of these GO-based nanomaterials is highlighted, employing techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman, and X-ray photoelectron spectroscopy to study their morphologies, structures, and chemical compositions. The development of GO-based electrochemical sensors and their pharmaceutical, medical, environmental, and food safety applications are discussed. Further, the effects of these GO-based nanomaterials and different electrochemical techniques (e.g., cyclic voltammetry, square wave voltammetry, linear sweep voltammetry, and differential pulse voltammetry) on the performance of various electrochemical sensors are addressed. [ABSTRACT FROM AUTHOR]

In this study, a highly sensitive electrochemical sensor for the detection of bisphenol A (BPA) was developed by modifying a screen-printed carbon electrode (SPCE) with silver nanoparticles (AgNPs) and graphene oxide (GO) composites. The electrochemical properties of the modified electrode interface were meticulously investigated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy, employing 1.0 mM [Fe(CN)6]3–/[Fe(CN)6]4– as a redox probe. The findings demonstrate that the AgNPs/GO/SPCE composite exhibits superior electrical conductivity and facilitates rapid electron transfer compared to both GO/SPCE and SPCE alone. The electrochemical behavior of BPA on the AgNPs/GO/SPCE electrode was comprehensively studied using CV, revealing exceptional electrocatalytic properties for BPA oxidation. To assess the analytical performance, differential pulse voltammetry was employed. Results unequivocally show a significant improvement in the electrochemical responses when using AgNPs/GO/SPCE. Calibration curves exhibited linear ranges of 0.25–2.19 μM with a remarkable limit of detection of 0.046 μM for BPA. Furthermore, the established method was applied for the determination of BPA in plastic products, achieving satisfactory reproducibility and recovery. This novel AgNPs/GO/SPCE-based sensor holds promise for the sensitive and reliable detection of BPA in various environmental and industrial applications. [ABSTRACT FROM AUTHOR]

The samples including Li 0.1 Co 0.8 Fe 2. 1 O 4 (LCFO) spinel ferrite (SF) and LCFO SF/graphene oxide (GO = 10 wt%, 15 wt%, and 20 wt%) nanocomposite were fabricated via the self-ignition route by following the bath ultra-sonication method. Their structural, morphological, and compositional properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray (EDX) spectroscopy, respectively. Moreover, the dielectric and magnetic properties at 300 K were studied using an impedance analyzer (IA) meter and vibrating sample magnetometer (VSM), respectively. All LCFO SF and GO-based LCFO nanocomposites exhibited a pure spinel matrix. The crystallite size was increased by the GO addition in the LCFO SF sample. The morphological analysis showed the non-uniform distribution of particles. The dielectric constant and loss exhibited behaviour consistent with Maxwell-Wagner interfacial polarization. The low tangent loss was observed at high frequency and ac conductivity analysis was increased with increasing the GO content. A slight enhancement in saturation magnetization was observed at 300 K with the addition of GO in LCFO SF. Hence, doping with GO offers a means to tune the dielectric, and magnetic response of the LCFO SF sample and is the best candidate for potential high-frequency application. [Display omitted] • The LCFO SF and LCFO/GO nanocomposites were prepared via the self-ignition route with an ultra-sonication technique. • The crystallite size was increased from 30 nm to 54 nm. • FTIR analysis along with XRD analysis also confirmed the spinel matrix. • SEM and TEM micrographs indicated the non-uniform distribution and agglomeration with the increasing GO. • The increase in GO leads to an improvement in the dielectric response. • The saturation magnetization was increased with the addition of GO. • The combination of LCFO SF with GO enhanced the dielectric, and magnetic properties, offering a candidate for high-frequency applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Flexible electrodes based on conversion-type materials have potential applications in low-cost and high-performance flexible sodium-ion batteries (FSIBs), owing to their high theoretical capacity and appropriate sodiation potential. However, they suffer from flexible electrodes with poor mechanical properties and sluggish reaction kinetics. In this study, freestanding CoS 2 nanoparticles coupled with graphene oxides and carbon nanotubes (CoS 2 /GO/CNTs) flexible films with robust and interconnected architectures were successfully synthesized. CoS 2 /GO/CNTs flexible film displays high electronic conductivity and superior mechanical properties (average tensile strength of 21.27 MPa and average toughness of 393.18 KJ m−3) owing to the defect bridge for electron transfer and the formation of the π–π interactions between CNTs and GO. In addition, the close contact between the CoS 2 nanoparticles and carbon networks enabled by the Co-N chemical bond prevents the self-aggregation of the CoS 2 nanoparticles. As a result, the CoS 2 /GO/CNTs flexible film delivered superior rate capability (213.5 mAh g−1 at 6 A g−1, better than most reported flexible anode) and long-term cycling stability. Moreover, the conversion reaction that occurred in the CoS 2 /GO/CNTs flexible film exhibited pseudocapacitive behavior. This study provides meaningful insights into the development of flexible electrodes with superior mechanical properties and electrochemical performance for energy storage. [ABSTRACT FROM AUTHOR]

KFeSO4F (KFSF) is considered a potential cathode due to the large capacity and low cost. However, the inferior electronic conductivity leads to poor electrochemical performance. Defect engineering can facilitate the electron/ion transfer by tuning electronic structure, thus providing favorable electrochemical performance. Herein, through the regulation of surface defect engineering in reduced graphene oxide (rGO), the Fe-C bonds were formed between KFSF and rGO. The Fe-C bonds formed work in regulating the Fe-3d orbital as well as promoting the migration ability of K ions and increasing the electronic conductivity of KFSF. Thus, the KFSF@rGO delivers a high capacity of 119.6 mAh g-1. When matched with a graphite@pitch-derived S-doped carbon anode, the full cell delivers an energy density of 250.5 Wh kg-1 and a capacity retention of 81.5% after 400 cycles. This work offers a simple and valid method to develop high-performance cathodes by tuning defect sites. [ABSTRACT FROM AUTHOR]

This work is focused on fabricating a counter electrode (CE) for application in a dye-sensitized solar cell (DSSC). Cobalt manganese oxide (CoMn2O4) nanoparticles (NPs) and its nanocomposite with graphene were prepared by a hydrothermal method. The nanocomposites of cobalt manganese oxide with graphene as CoMn2O4/(graphene)x (where x = 0.2, 0.4, and 0.6) were synthesized as an electrode material, and a cell was fabricated for the x = 0.6 nanocomposite to investigate the activity for use in DSSCs. These nanocomposites were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier transform infrared (FTIR) spectroscopy. SEM analysis revealed the nature of the particles, and the average grain size was in good agreement with XRD results. EDX showed the ratio of the respective samples. The XRD pattern showed the hexagonal structure of CoMn2O4 NPs with an average size of 39.45 nm. The FTIR spectrum indicated O–H stretching bonds and the vibrational bending of MnO at the interstitial sites. For electrochemical analysis, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed. Through CV analysis, an anodic peak current (Ipa) was observed at 41.42 µA, while the cathodic peak current (Ipc) was observed at −37.13 µA, and peak-to-peak separation (ΔEpp) = 0.31 V for CoMn2O4 NPs. For graphene, Ipa = 180.45 µA, Ipc = −230 µA, and ΔEpp = 0.25 V, while Ipa = 100.23 µA, Ipc = 80.65 µA, and ΔEpp = 0.16 V for the CoMn2O4/graphene (x = 0.6) nanocomposite, which also showed excellent electrocatalytic properties. The charge transfer mechanism on the surface of the electrode was found to have rapid oxidation–reduction behavior and can be used as an alternative to platinum as the CE in the DSSC. The CV analysis of the CoMn2O4/graphene (x = 0.6) nanocomposite-based DSSC showed that the Ipa current was observed at 26.85 mA, while the Ipc current was observed at −27.25 mA in the two-electrode system. The Rs values for CoMn2O4/graphene with x = 0.2, 0.4, and 0.6 were 142.80 Ω, 141.33 Ω, 135.18 Ω, and 131.18 Ω, respectively, as an electrode material. The exchange current density J = 2.13 × 10−3 A/cm2 was found using the charge transfer resistance value (Rct = 6.03 Ω cm2) and was verified by the Tafel curve. [ABSTRACT FROM AUTHOR]

The use of hydrophilic polymer membranes derived from nanocomposites for the treatment of industrial wastewaters has garnered significant attention lately. When producing membranes, the fouling problems of these membranes may be lessened by adding hydrophilic additives to the polymer solution. In order to create the membranes by the phase inversion approach, 0.8 weight percent of polyethersulfone (PES) solution was mixed with a combination (1:1) of graphene oxide:titanium dioxide nanoparticles (GO:TiO2 NPs) at various weight percentages (0.2, 0.4, 0.6, and 0). The absence of spectral peaks at 899 and 1669 cm-1 in the completed membranes, as determined by FTIR studies, suggests that the GO:TiO2 NPs component's hydrolytic breakdown caused the membrane structure's pores to develop. The membrane topology was rough with a wider range of heights and abnormalities at low NP concentrations, as the histogram of the 3D AFM pictures illustrates. On the other hand, the 2D photos showed that the surface smoothed out and had fewer peaks and valleys at high NP concentrations, which decreased the surface's roughness. Surface scanning electron microscopy pictures demonstrated that when the membrane's structure evolved from narrow to broad porosity with uneven expansion of porous patches, adding more nanoparticles increased the water flow. However, cross-sectional SEM pictures showed that the membrane's constituent parts were a thick porous layer with micropores and elongated finger structures that resembled pores, and a thin skin layer. The membrane's porosity increased with increasing NP concentration, as demonstrated by porosity calculations and contact angle measurements. This improved selectivity, made the membrane less prone to fouling, and made cleaning safer and easier, particularly for hydrophilic foulants like proteins and polysaccharides. The addition of NPs resulted in an estimated 83% and 92% increase in the flow of pure water and bovine serum albumin (BSA), respectively. However, the BSA rejection initially dropped before increasing once again. [ABSTRACT FROM AUTHOR]

Pathogen-induced infections and the rise of antibiotic-resistant bacteria, such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), pose significant global health challenges, emphasizing the need for new antimicrobial strategies. In this study, we synthesized graphene oxide (GO)-based composites functionalized with silver nanoparticles (AgNPs) and copper nanoparticles (CuNPs) as potential alternatives to traditional antibiotics. The objective is to assess the antibacterial properties of these composites and explore their efficacy against E. coli and S. aureus, two common bacterial pathogens. The composites are prepared using eco-friendly and conventional methods to ensure effective nanoparticle attachment to the GO surface. Structural and morphological characteristics are confirmed through SEM, AFM, EDS, XRD, UV-vis, FTIR, and Raman spectroscopy. The antibacterial efficacy of the composites is tested through disk diffusion assays, colony-forming unit (CFU) counts, and turbidimetry analysis, with an emphasis on understanding the effects of different nanoparticle concentrations. The results demonstrated a dose-dependent antibacterial effect, with GO/AgNP-1 showing superior antibacterial activity over GO/AgNP-2, particularly at lower concentrations (32.0 μg/mL and 62.5 μg/mL). The GO/CuNP composite also exhibited significant antibacterial properties, with optimal performance at 62.5 μg/mL for both bacterial strains. Turbidimetry analysis confirmed the inhibition of bacterial growth, especially at moderate concentrations, although slight nanoparticle aggregation at higher doses reduced efficacy. Lastly, both GO/AgNP and GO/CuNP composites demonstrated significant antibacterial potential. The results emphasize the need to fine-tune nanoparticle concentration and refine synthesis techniques to improve their efficacy, positioning these composites as strong contenders for antimicrobial use. [ABSTRACT FROM AUTHOR]

Microfluidics cell encapsulation offers a way to mimic a 3D microenvironment that supports cell growth and proliferation, while also protecting cells from environmental stress. This technique has found extensive applications in tissue engineering and cell therapies. Several studies have demonstrated the advantages of graphene oxide (GO) as an osteogenic inducer; however, the significance of GO on stem cell fate in the single-cell state is still unclear. Here, a microfluidics-based approach is developed for continuous encapsulation of mesenchymal stem cells (MSCs) at the single-cell level using alginate microgels. So, single-layer graphene oxide (slGO) nanosheet is used to be encapsulated inside the alginate droplets. The results of AFM and SEM show that slGO can increase the roughness and reduce the stiffness of alginate hydrogels. The Young's modulus of the alginate and alginate-slGO was obtained as 1414 kPa and 985.9 kPa, respectively. Live/dead assay and fluorescence microscopy images illustrate that slGO can maintain the viability and proliferation of microencapsulated hBMSCs. The obtained results show that slGO increases the mineralization of the encapsulated hBMSCs, so that microgels containing hBMSCs gradually became opaque during 21 days of culture. RT-qPCR results indicate that the expression of OCN, Runx2, and ALP in the alginate-slGO microgels is significantly higher than in the alginate microgels. The expression of OCN and Runx2 in the alginate-slGO microgels is 4.27 and 5.87-fold higher than in the alginate microgels, respectively. It can be concluded that low doses of slGO nanosheets have the potential to be utilized in the development of tissue engineering and bone regeneration. This finding offers a new method for creating injectable tissue transplants that are minimally invasive. [ABSTRACT FROM AUTHOR]

This study explores the impact of a graphene oxide (GO)/nano silica (NS) hybrid (GO/NS) filler on the diffusion characteristics of natural rubber (NR) composites when exposed to toluene, xylene, and hexane solvents. The lowest solvent uptake is observed for NR GO/NS 3 (3 phr), which is attributed to forming a robust filler network within the composite. The calculation of crosslink density using the Flory‐Rehner equation reveals significantly higher values for NR GO/NS 3, indicating good crosslinking density in the presence of the hybrid filler. Furthermore, molecular mass between crosslinks (Mc) is calculated, demonstrating a favorable fit with the Affine model. The investigation extends to theoretical modeling, where the Korsemeyer–Peppas and Peppas–Sahlin models are employed to predict solvent uptake behavior. Strikingly, the experimental values exhibit a strong alignment with the Peppas–Sahlin model. This comprehensive analysis provides valuable insights into the diffusion behavior of graphene oxide/nano silica (GO/NS) hybrid‐reinforced natural rubber latex in organic solvents, highlighting potential applications in areas such as solvent‐resistant coatings, barrier materials for chemical storage, and enhanced performance in protective gloves and seals used in harsh chemical environments. [ABSTRACT FROM AUTHOR]

The Li-ferrite and graphene oxide (GO) nanocomposites, denoted as (Li 0.5-x/2 ZnₓFe 2.5-x/2 O 4 : x = 0.25), were produced through ultrasonication. The wet method generated Li-ferrite, while the Hummers' method synthesized the GO. X-ray diffraction (XRD) was used to validate the development of Li-ferrite and GO in the nanocomposites. The dimensions of the crystal were determined between 41 and 52 nm, and the porosity of the composites increased with the higher quantity of GO. The scanning electron micrographs (SEM) of ferrites illustrated the formation of uniform and well-defined grains with consistent shapes, exhibiting properties well-suited for effective microwave absorption. The electrical resistance of spinel ferrite was measured at approximately 3.34 × 1011 Ω-cm and significantly lowered as the fraction of GO increased at ambient temperature. As per Maxwell Wagner's model, the electrical permittivity exhibited interfacial polarization with distinct real and imaginary components. The AC conductivity exhibited a positive correlation with the GO content due to the conductive properties of GO and the improved charge hopping mechanism. The frequency exponent parameter's value falls from 0.36 to 0.95 b y the Jonscher's Power law. The magnetic susceptibility of all the samples exhibited a progressive decrease as the temperature increased. The choice of using lithium-based ferrite as filler is made to strengthen the ferrite/GO composites and improve their magnetic and electrical properties. This is undertaken to harness these composites for high-frequency applications, such as their use as microwave absorbers in microwave devices. [ABSTRACT FROM AUTHOR]

Bacterial cellulose composites hold promise as renewable bioinspired materials for industrial and environmental applications. However, their use as free-standing water filtration membranes is hindered by low compressive strength, fouling, and poor contaminant selectivity. This study investigates the potential of bacterial cellulose-graphene oxide composites membranes for fouling resistance in pressure-driven filtration. Graphene oxide dispersed in poly(ethylene glycol) (PEG-400) is incorporated as a reinforcing filler into 3D network of bacterial cellulose using an in-situ synthesis method. The effect of graphene oxide on in situ fermentation yield and the formation of percolated-network in the composites shows that the optimal membrane properties are reached at a graphene oxide loading of 2 mg/mL. The two-dimensional graphene oxide nanosheets uniformly dispersed into the matrix of bacterial cellulose nanofibers via hydrogen-bonded interactions demonstrated nearly twofold higher water flux (380 L m−2 h−1) with a molecular weight cut-off ranging between 100–200 KDa and a sixfold increase in wet compression strength than pristine BC. When exposed to synthetic organic foulants and bacterial rich feed solutions, the composite membranes showed more than 95% flux recovery. Additionally, the membranes achieved over 95% rejection of synthetic natural organic matter and bacterial rich solutions, showcasing their enhanced fouling resistance and selectivity. [ABSTRACT FROM AUTHOR]

This study investigates the fabrication and characterization of electrospun poly (ε-caprolactone)/poly (vinyl pyrrolidone) (PCL/PVP) fibers integrated with a nanocomposite of chitosan, silver nanocrystals, and graphene oxide (ChAgG), aimed at developing advanced wound dressing materials. The ChAgG nanocomposite, recognized for its antimicrobial and biocompatible properties, was incorporated into PCL/PVP fibers through electrospinning techniques. We assessed the resultant fibers' morphological, physicochemical, and mechanical properties, which exhibited significant enhancements in mechanical strength and demonstrated effective antimicrobial activity against common bacterial pathogens. The findings suggest that the PCL/PVP-ChAgG fibers maintain biocompatibility and facilitate controlled therapeutic delivery, positioning them as a promising solution for managing chronic and burn-related wounds. This study underscores the potential of these advanced materials to improve healing outcomes cost-effectively, particularly in settings plagued by high incidences of burn injuries. Further clinical investigations are recommended to explore these innovative fibers' full potential and real-world applicability. [ABSTRACT FROM AUTHOR]

In this work we introduce GrapheNet, a deep learning framework based on an Inception-Resnet architecture using image-like encoding of structural features for the prediction of the properties of nanographenes. The model is validated on datasets of computed structure/property data on graphene oxide and defected graphene nanoflakes. By exploiting the planarity of quasi-bidimensional systems and through encoding structures into images, and leveraging the flexibility and power of deep learning in image processing, Graphenet achieves significant accuracy in predicting the physicochemical properties of nanographenes. This approach is able to efficiently encode structures composed of hundreds of atoms, scaling efficiently with the size of the model and enabling the prediction of the properties of large systems, which contrasts with the limitations of current atomistic-level representations for deep learning applications. The approach proposed based on image encoding exhibit a significant numerical accuracy and outperforms the computational efficiency of current representations of materials at the atomistic level, with significant advantages especially in the representation of nanostructures and large planar systems. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li-S) batteries offer a high theoretical energy density but suffer from poor cycling stability and polysulfide shuttling, which limits their practical application. To address these challenges, we developed a PANI-modified MoS2-NG composite, where MoS2 nanoflowers were uniformly grown on graphene oxide (GO) through PANI modification, resulting in an increased interlayer spacing of MoS2. This expanded spacing exposed more active sites, enhancing polysulfide adsorption and catalytic conversion. The composite was used to prepare MoS2-NG/PP separators for Li-S batteries, which achieved a high specific capacity of 714 mAh g−1 at a 3 C rate and maintained a low capacity decay rate of 0.085% per cycle after 500 cycles at 0.5 C. The larger MoS2 interlayer spacing was key to improving redox reaction kinetics and suppressing the shuttle effect, making the MoS2-NG composite a promising material for enhancing the performance and stability of Li-S batteries. [ABSTRACT FROM AUTHOR]

We report passively Q-switched pulse operation through an erbium-doped fiber laser (EDFL) utilizing graphene oxide/titania (GO/TiO2) nanorods as a saturable absorber. The GO/TiO2 nanorods were fabricated using a Sol–gel-assisted hydrothermal method. The optical and physical characterization of the GO/TiO2 was then characterized using a field-emission-scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and diffuses reflectance spectroscopy (DRS). To investigate the performance of the Q-switched EDFL based on the GO/TiO2 SA, the prepared nanorods were mechanically deposited on the fiber ferrule employing adhesion effects of in-dex-matching gel. This integration of the nanorod SA resulted in a self-starting Q-switching opera-tion initiated at a pump power of 17.5 mW and sustained up to 306.9 mW. When the pump range was tuned from 17.5 to 306.9 mW, the emission wavelength varied from 1564.2 to 1562.9 nm, pulse repetition rates increased from 13.87 kHz to 83.33 kHz, and pulse width decreased from 30.27 µs to 3.75 µs. Moreover, at the maximum pump power of 306.9 mW, the laser exhibited an average output power of 0.74 mW, a peak power of 1.54 mW, and a pulse energy of 8.88 nJ. Furthermore, this study investigates the GO/TiO2 damage threshold and prolonged stability of the proposed EDFL system. [ABSTRACT FROM AUTHOR]

Conductive polymer composites (CPCs) with nanocarbon fillers are at the high end of modern materials science, advancing current electronic applications. Herein, we establish the interplay between the chemistry and electrophysical properties of reduced graphene oxide (rGO), separately and as a filler for CPCs with the segregated structure conferred by the chemical composition of the initial graphene oxide (GO). A set of experimental methods, namely X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy, van der Paw and temperature-dependent sheet resistance measurements, along with dielectric spectroscopy, are employed to thoroughly examine the derived materials. The alterations in the composition of oxygen groups along with their beneficial effect on nitrogen doping upon GO reduction by hydrazine are tracked with the help of XPS. The slight defectiveness of the graphene network is found to boost the conductivity of the material due to facilitating the impact of the nitrogen lone-pair electrons in charge transport. In turn, a sharp drop in material conductivity is indicated upon further disruption of the π-conjugated network, predominantly governing the charge transport. Particularly, the transition from the Mott variable hopping transport mechanism to the Efros–Shklovsky one is signified. Finally, the impact of rGO chemistry and physics on the electrophysical properties of CPCs with the segregated structure is evaluated. Taken together, our results give a hint at how GO chemistry manifests the properties of rGO and the CPC derived from it, offering compelling opportunities for their practical applications. [ABSTRACT FROM AUTHOR]

To address the rapidly growing demand for high performance of lithium-ion batteries (LIBs), the development of high-capacity anode materials should focus on the practical perspective of a facile synthetic process. In this work, iron oxide nanoparticles (Fe3O4 NPs) in situ grown on the surface of reduced graphene oxide (rGO), denoted as Fe3O4 NPs@rGO, were prepared through a facile one-pot synthesis under the wet-colloidal conditions. The synthesized Fe3O4 NPs showed that uniform Fe3O4 NPs, with a size of around 9 nm, were distributed on the rGO surfaces. When applied as an anode material for LIBs, the Fe3O4 NPs@rGO anode revealed a high reversible capacity of 1191 mAh g−1 at 1.0 A g−1 after 200 cycles. It also exhibited excellent rate performance, achieving 608 mAh g−1 at a current density of 5.0 A g−1 over 500 cycles, with improved electronic and ionic conductivities due to the rGO template. This suggested that practically available anode materials can be developed through our one-pot synthesis by in situ growing the Fe3O4 NPs. [ABSTRACT FROM AUTHOR]

Water motion‐induced energy harvesting has emerged as a prominent means of facilitating renewable electricity from the interaction between nanostructured materials and water over the past decade. Despite the growing interest, comprehension of the intricate solid–liquid interfacial phenomena related to solid state physics remains elusive and serves as a hindrance to enhancing energy harvesting efficiency up to the practical level. Herein, the study introduces the energy harvester by utilizing inversion on the majority charge carrier in graphene materials upon interaction with water molecules. Specifically, various metal electrode configurations are employed on reduced graphene oxide (rGO) to unravel its distinctive charge carriers that experience the inversion in semiconductor type upon water contact, and exploit this characteristic to leverage the efficacy of generated electricity. Through the strategic arrangement of the metal electrodes on rGO membrane, the open‐circuit voltage (Voc) and short‐circuit current (Isc) have exhibited a remarkable augmentation, reaching 1.05 V and 31.6 µA, respectively. The demonstration of effectively tailoring carrier dynamics via electrode configuration expands the practicality by achieving high power density and elucidating how the water‐induced carrier density modulation occurs in 2D nanomaterials. [ABSTRACT FROM AUTHOR]

Biochar is a carbon-rich material, produced through the thermochemical conversion of various organic biomass materials, and it has garnered significant attention due to its versatile applications. In recent years, there has been a surge in research, focusing on the modification of biochar to enhance its properties and effectiveness for specific applications. With the rapid development of large-scale biochar production techniques, there has been a significant increase in literature discussing modified biochar and its applications. This review provides a comprehensive overview of various modification methods applied to biochar, including physical, chemical, and biological treatments. These methods include alkalis and acids, polymer coatings, biological inoculation, metal-mediated modifications, heteroatom doping, and the incorporation of other composites such as g-C3N4, ionic liquids, quantum dots, and graphene oxides. These modifications aim to adjust pore size distribution, optimize surface chemistry, and incorporate additives to enhance specific functionalities. Recent research shows a growing interest in modifying biochar, with efforts focused on maximizing its potential to address current environmental and agricultural issues. Thus, in this review, a brief description of the synthesis of the modified biochar materials and their enhanced applicability in specific fields has been discussed along with insights and direction for future research and development initiatives. [ABSTRACT FROM AUTHOR]

Background: The world society is still suffering greatly from waterborne infections, with developing countries bearing most of the morbidity and death burden, especially concerning young children. Moreover, microbial resistance is one of the most prevalent global problems that extends the need for self-medication and the healing period, or it may be linked to treatment failure that results in further hospitalization, higher healthcare expenses, and higher mortality rates. Thus, innovative synthesis of new antimicrobial materials is required to preserve the environment and enhance human health. Results: The present study highlighted a simple and cost-effective approach to biosynthesize a chitosan/graphene oxide/zinc oxide nanocomposite (CS/GO/ZnO) alone and immobilized in a macroporous cryogel as a new antimicrobial agent. Bacillus subtilis ATCC 6633 was used as a safe and efficient bio-nano-factory during biosynthesis. The formation of CS/GO/ZnO was confirmed and characterized using different analyses including ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), selective area diffraction pattern (SADP), Zeta analyses, scanning electron microscope (SEM) and transmission electron microscopy (TEM). GO combined with ZnO NPs successfully and displayed an adsorption peak at 358 nm. The XRD results showed the crystalline composition of the loaded ZnO NPs on GO sheets. FTIR spectrum confirmed the presence of proteins during the synthesis which act as stabilizing and capping agents. The nanocomposite has a high negative surface charge (-32.8 ± 5.7 mV) which increases its stability. SEM and TEM showing the size of biosynthesized ZnO-NPs was in the range of 40–50 nm. The CS/GO/ZnO alone or immobilized in cryogel revealed good antimicrobial activities against B. cereus ATCC 14,579, Escherichia coli ATCC 25,922, and Candida albicans ATCC 10,231 in a dose-dependent manner. The CS/GO/ZnO cryogel revealed higher antimicrobial activity than GO/ZnO nanocomposite and standard antibiotics (amoxicillin and miconazole) with inhibition zones averages of 24.33 ± 0.12, 15.67 ± 0.03, and 17.5 ± 0.49 mm, respectively. The MIC values of the prepared nanocomposite against B. cereus, E. coli, and C. albicans were 80, 80, and 90 µg/ml compared to standard drugs (90, 120 and 150 µg/ml, respectively). According to the TEM ultrastructure studies of nanocomposite-treated microbes, treated cells had severe deformities and morphological alterations compared to the untreated cells including cell wall distortion, the separation between the cell wall and plasma membrane, vacuoles formation moreover complete cell lyses were also noted. In the cytotoxicity test of CS/GO/ZnO alone and its cryogel, there was a significant reduction (p˂0.05) in cell viability of WI-38 normal lung cell line after the concentration of 209 and 164 µg/ml, respectively. It showed the low toxic effect of the nanocomposite and its cryogel on the WI-38 line which implies its safety. In addition, water treatment with the CS/GO/ZnO cryogel decreased turbidity (0.58 NTU), total coliform (2 CFU/100 ml), fecal coliform (1 CFU/100 ml), fecal Streptococcus (2 CFU/100 ml), and heterotrophic plate counts (53 CFU/1 ml) not only in comparison with the chlorine-treated samples (1.69 NTU, 4 CFU/100 ml, 6 CFU/100 ml, 57 CFU/100 ml, and 140 CFU/1 ml, respectively) but also with the raw water samples (6.9 NTU, 10800 CFU/100 ml, 660 CFU/100 ml, 800 CFU/100 ml, and 4400 CFU/1 ml, respectively). Moreover, cryogel significantly decreased the concentration of different heavy metals, especially cobalt compared to chlorine (0.004 ppm, 0.002 ppm, and 0.001 ppm for raw water, chlorine-treated, and cryogel-treated groups, respectively) which helped in the reduction of their toxic effects. Conclusion: This study provides an effective, promising, safe, and alternative nanocomposite to treat different human and animal pathogenic microbes that might be used in different environmental, industrial, and medical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Enhancing the flame retardancy of epoxy (EP) resins typically entailed a trade-off with other physical properties. Herein, hyperbranched poly(amidoamine) (HPAA) and phytic acid (PA) were used to functionalize graphene oxide (GO) via electrostatic self-assembly in water to prepare a phosphorus-nitrogen functionalized graphene oxide nanosheet (PN-GOs), which could be utilized as high efficient flame-retardant additive of epoxy resin without sacrificing other properties. The PN-GOs demonstrated improved dispersion and compatibility within the EP matrix, which resulted in significant concurrent enhancements in both the mechanical performance and flame-retardant properties of the PN-GOs/EP nanocomposites over virgin EP. Notably, the incorporation of just 1.0 wt% PN-GOs yielded a 20.4, 6.4 and 42.7 % increases in flexural strength, flexural modulus and impact strength for the PN-GOs/EP nanocomposites, respectively. Furthermore, simultaneous reductions were achieved in the peak heat release rate (pHRR) by 60.0 %, total smoke production (TSP) by 43.0 %, peak CO production rate (pCOP) by 57.9 %, and peak CO 2 production rate (pCO 2 P) by 63.9 %. This study presented a facile method for the design of GO-based nano flame retardants, expanding their application potential in polymer-matrix composites. [ABSTRACT FROM AUTHOR]

Background: Bone grafts are extensively used for repairing bone defects and voids in orthopedics and dentistry. Moldable bone grafts offer a promising solution for treating irregular bone defects, which are often difficult to fill with traditional rigid grafts. However, practical applications have been limited by insufficient mechanical strength and rapid degradation. Methods: This study developed a ceramic composite bone graft composed of calcium sulfate (CS), β-tricalcium phosphate (β-TCP) with/without graphene oxide (GO) nano-particles. The biomechanical properties, degradation rate, and in-vitro cellular responses were investigated. In addition, the graft was implanted in-vivo in a critical-sized calvarial defect model. Results: The results showed that the compressive strength significantly improved by 135% and the degradation rate slowed by 25.5% in comparison to the control model. The addition of GO nanoparticles also improved cell compatibility and promoted osteogenic differentiation in the in-vitro cell culture study and was found to be effective at promoting bone repair in the in-vivo animal model. Conclusions: The mixed ceramic composites presented in this study can be considered as a promising alternative for bone graft applications. [ABSTRACT FROM AUTHOR]

Graphene and its derivatives are widely used in tissue-engineering scaffolds, especially in the form of hydrogels. This is due to their biocompatibility, electrical conductivity, high surface area, and physicochemical versatility. They are also used in tissue engineering. Tissue engineering is suitable for 3D printing applications, and 3D printing makes it possible to construct 3D structures from 2D graphene, which is a revolutionary technology with promising applications in tissue and organ engineering. In this review, the recent literature in which graphene and its derivatives have been used as the major components of hydrogels is summarized. The application of graphene and its derivative-based hydrogels in tissue engineering is described in detail from different perspectives. [ABSTRACT FROM AUTHOR]

An alternative biomarker for assessing the cyanide levels in postmortem materials is crucial for investigating acute cyanide intoxication. Herein, an aptamer–ligand biorecognition system with high specificity was developed to detect acute cyanide poisoning via its secondary metabolite, 2-amino-2-thiazoline-4-carboxylic acid (ATCA). Potential aptamers were screened from a random library of 66-base single-stranded DNA using GO-SELEX, with individual aptamers being identified through single-stranded DNA sequencing. Molecular docking was employed to predict the affinity of these aptamers toward ATCA and selected counter-targets; these predictions were confirmed using thermodynamic analysis with an isothermal titration calorimeter. Owing to its label-free biomolecular binding interactions, Apt46 exhibited the highest affinity against ATCA and notable selectivity against structurally similar counter-targets. Thus, an amino-tagged Apt46 binding aptamer was attached to a carbon electrode modified with EDC–NHS-activated graphene oxide. The binding of Apt46 to ATCA was quantified by measuring current changes using differential pulse voltammetry. The aptasensor achieved a detection limit of 0.05 µg/mL and demonstrated suitability for detecting ATCA across various biological matrices, with the high recovery percentages ranging from 92.29 to 114.22%. Overall, the proposed ATCA aptasensor is promising for identifying ATCA metabolites in cases of acute cyanide exposure. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is the most common malignant tumor of male genitourinary system, ranking second among all male malignant tumors and showing a trend toward younger age. However, for metastatic prostate cancer, commonly used androgen deprivation therapy combined with docetaxel chemotherapy or neoendocrine therapy is prone to complications (incontinence, erectile dysfunction, and rectal damage), resulting in reduced quality of life or serious side effects for patients. Therefore, the designed GO-DAA-Ce6 nanoparticles were constructed to couple graphene oxide and Ce6 via diacylhydrazine adipate (DAA) as a bridge. The combination therapy of PTT and PDT is made possible by the outstanding photothermal conversion ability of GO and the high singlet oxygen generation of Ce6. GO-DAA-Ce6 demonstrated low toxicity and great biocompatibility in cytotoxicity and hemolysis assays. According to the outcomes of in vitro anti-tumor tests, GO-DAA-Ce6 greatly outperformed the photothermal and photodynamic efficacy of GO alone and Ce6 alone in terms of tumor suppression rates. The findings of the anticancer mechanism study point to the possibility that GO-DAA-Ce6 may cause cancer cells to undergo apoptosis and necrosis by initially damaging suborganelles such mitochondria. The straightforward design of the photothermal and photodynamic collaboration platform kills prostate cancer effectively and offers a general method for the treatment of various conditions including inflammation and skin infections. [ABSTRACT FROM AUTHOR]

Graphene-based nanomaterials have been proved to be robust sorbents for efficient removal of environmental contaminants including arsenic (As). Biobased graphene oxide (bGO-P) derived from sugarcane bagasse via pyrolysis, GO-C via chemical exfoliation, and magnetite nanoparticles (FeNPs) via green approach using Azadirachta indica leaf extract were synthesized and characterized by Ultraviolet-Visible Spectrophotometer (UV-vis.), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), mean particle size and Scanning electron microscopy (SEM) along with Energy dispersive spectroscopy (EDX) analysis. Compared to cellulose and hemicellulose, the lignin fraction was less in the precursor material. The GOC, bGO-P and FeNPs displayed maximum absorption at 230, 236, and 374 nm, respectively. FTIR spectrum showed different functional groups (C-OH, C-O-C, COOH and O-H) modifying the surfaces of synthesized materials. Graphene based nanomaterials showed clustered dense flakes of GO-C and thin transparent flakes of bGO-P. Elemental composition by EDX analysis of GO-C (71.26% C and 27.36% O), bGO-P (74.54% C and 24.61% O) and FeNPs (55.61% Fe, 4.1% C and 35.72% O) confirmed the presence of carbon, oxygen, and iron in synthesized nanomaterials. Sorption study was conducted with soil amended with different doses of synthesized nanomaterials (10, 50 and 250 mg) and exposed to 100, 300 and 500 ppm of As. Arsenic concentrations were estimated by colorimetry and atomic absorption spectroscopy (AAS). GO-C, bGO-P, and FeNPs showed substantial As removal efficiency i.e., 81 to 99.3%, 65 to 98.8% and 73.1–89.9%, respectively. Green synthesis of bGO-P and magnetite nanoparticles removed substantial amounts of As compared to GO-C and can be effectively deployed for As removal or immobilization. Higher and medium sorbent doses (250 and 50 mg) exhibited greater As removal and data was best fitted for Freundlich isotherm evidencing favorable sorption. Nevertheless, at low sorbent doses, data was best fitted for both models. Newly synthesized nanomaterials emerged as promising materials for As removal strategy for soil nano-remediation and can be effectively deployed in As contaminated soils. [ABSTRACT FROM AUTHOR]

Simultaneous detection of multiple neurotransmitters and their related activities is crucial for enhancing our understanding of complex neurological mechanisms and disorders. In this study, we developed a flexible, high-sensitivity multi-electrodes array probe capable of concurrent detection of four neurotransmitters: dopamine, serotonin, acetylcholine and glutamate. The probe was fabricated on a polyimide substrate with 16 circular gold-film electrodes. These electrodes were modified with PEDOT/GluOx and PEDOT/ChOx for enzymatic detection of glutamate and acetylcholine, and with rGO/PEDOT/Nafion for the detection of dopamine and serotonin. Our electrochemical sensor achieved sensitivities of 184.21 and 219.29 μA/μM cm2 for glutamate and acetylcholine, respectively, with limits of detection (LOD) of 0.0242 and 0.0351 μM within a concentration range of 0.1–100 μM. For dopamine and serotonin, the sensor showed sensitivities of 195.9 and 181.2 μA/μM cm2, respectively, with LOD of 0.4743 and 0.3568 μM. This research advances the field of neurochemical sensing and provides valuable insights into the balance of neurotransmitters associated with neurological disorders. These insights improve diagnostic and therapeutic strategies. [ABSTRACT FROM AUTHOR]

Sulfate anions (SO42−) are pivotal in various scientific and industrial domains, including mineralogy, biology, and materials science. While extensive research has elucidated sulfate hydration in bulk solids, liquids, and gaseous clusters, a significant gap persists in understanding sulfate interactions within two-dimensional materials, particularly graphene oxide (GO) nanosheets. This study investigates the intricate hydration phenomena and novel triple-interlayer lattice configurations that emerge from sulfate intercalation in GO nanosheets. Utilizing a straightforward methodology for obtaining precise X-ray measurements of confined nanospaces, we analyzed the temperature-dependent behavior and structural characteristics of these systems. Our findings reveal how sulfate ions modulate interlayer spacing, the dynamics of GO layers, and phase transitions. This research offers an atomic-scale understanding of hybrid hydration behaviors within confined SO4-H2O nano-environments, advancing our knowledge of sulfate interactions in two-dimensional materials. [ABSTRACT FROM AUTHOR]

Background/Objectives: Peripheral nerve injuries (PNIs) are a debilitating problem, resulting in diminished quality of life due to the continued presence of both chronic and acute pain. The current standard of practice for the repair of PNIs larger than 10 mm is the use of autologous nerve grafts. Autologous nerve grafts have limitations that often result in outcomes that are not sufficient to remove motor and sensory impairments. Bio-mimetic nanocomposite scaffolds combined with mesenchymal stem cells (MSCs) represent a promising approach for PNIs. In this study, we investigated the potential of an electrospun wrap of polycaprolactone (PCL) + graphene oxide (GO), with and without xenogeneic human adipose tissue-derived MSCs (hADMSCs) to use as a platform for neural tissue engineering. Methods: We evaluated, in vitro and in vivo, the potential of the nerve wrap in providing support for axonal growth. To establish the rat sciatic nerve defect model, a 10 mm long limiting defect was created in the rat sciatic nerve of 18 Lewis rats. Rats treated with the nanocomposites were compared with autograft-treated defects. Gait, histological, and muscle analyses were performed after sacrifice at 12 weeks post-surgery. Results: Our findings demonstrate that hADMSCs had the potential to transdifferentiate into neural lineage and that the nanocomposite successfully delivered hADMSCs to the injury site. Histologically, we show that the PCL + GO nanocomposite with hADMSCs is comparable to the autologous nerve graft, to support and guide axonal growth. Conclusions: The novel PCL + GO nerve wrap and hADMSCs used in this study provide a foundation on which to build upon and generate future strategies for PNI repair. [ABSTRACT FROM AUTHOR]

Once widely utilised in both human and veterinary medicine, tetracycline antibiotics are now recognised as major environmental pollutants with detrimental effects on the environment and human health. Concerns regarding allergic responses, gastrointestinal problems, and diseases resistant to antibiotics are raised by their persistence in soil, groundwater, and surface water. The production of a tungsten disulfide-graphene oxide nanocomposite for tetracycline degradation under varied light sources is presented in this work. The successful incorporation of tungsten disulfide on graphene oxide structures was confirmed by characterization using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and X-ray Diffraction (XRD). This revealed characteristic peaks for hydroxyl (3328 cm-1), carbonyl (1732 cm-1), alkene (1583 cm-1), and ether (1044 cm-1) bonds, as well as sulphur bonding (500 to 739 cm-1). With a D-spacing of 2.24 nm, the tungsten disulphide-graphene oxide nanocomposite had a strong peak at 2θ = 15.5°corresponds to the (002) plane, as shown by X-ray diffraction. A distinctive GO peak was found at 2θ = 10.1°, which corresponds to the plane (002). With light emitting diodes (95.67%), fluorescent lights (81.28%), and ultraviolet-visible light (88.09%), the nanocomposite in a photoreactor showed excellent photocatalytic efficiency. The better performance of the tungsten disulfide-graphene oxide nanocomposite under varying illumination circumstances, as determined by the Langmuir-Hinshelwood (LH) model, presents a viable and sustainable option for tetracycline degradation in water purification. This technique tackles a long-term strategy for tetracycline photocatalytic degradation in water purification under different illumination scenarios. [ABSTRACT FROM AUTHOR]

A novel sandwich-type electrochemical aptasensor based on supramolecularly immobilized affinity bioreceptor was prepared via host–guest interactions. This method utilizes an adamantane-modified, target-responsive hairpin DNA aptamer as a capture molecular receptor, along with a perthiolated β-cyclodextrin (CD) covalently attached to a gold-modified electrode surface as the transduction element. The proposed sensing strategy employed an enzyme-modified aptamer as the signalling element to develop a sandwich-type aptasensor for detecting prostate-specific antigen (PSA). To achieve this, screen-printed carbon electrodes (SPCEs) with electrodeposited reduced graphene oxide (RGO) and gold nanoferns (AuNFs) were modified with the CD derivative to subsequently anchor the adamantane-modified anti-PSA aptamer via supramolecular associations. The sensing mechanism involves the affinity recognition of PSA molecules on the aptamer-enriched electrode surface, followed by the binding of an anti-PSA aptamer–horseradish peroxidase complex as a labelling element. This sandwich-type arrangement produces an analytical signal upon the addition of H2O2 and hydroquinone as enzyme substrates. The aptasensor successfully detected the biomarker within a concentration range of 0.5 ng/mL to 50 ng/mL, exhibiting high selectivity and a detection limit of 0.11 ng/mL in PBS. [ABSTRACT FROM AUTHOR]

The use of nanoparticles in the industry carries the risk of their release into the environment. Based on the presumption that the primary graphene oxide (GO) toxicity mechanism is reactive oxygen species production in the cell, the question arises as to whether well-known antioxidants can protect the cell or significantly reduce the effects of GO. This study focused on the possible remedial effect of vitamin C in Acheta domesticus intoxicated with GO for whole lives. The reproduction potential was measured at the level of Vitellogenin (Vg) gene expression, Vg protein expression, hatching success, and share of nutrition in the developing egg. There was no simple relationship between the Vg gene's expression and the Vg protein content. Despite fewer eggs laid in the vitamin C groups, hatching success was high, and egg composition did not differ significantly. The exceptions were GO20 and GO20 + Vit. C groups, with a shift in the lipid content in the egg. Most likely, ascorbic acid impacts the level of Vg gene expression but does not affect the production of Vg protein or the quality of eggs laid. Low GO concentration in food did not cause adverse effects, but the relationship between GO toxicity and its concentration should be investigated more thoroughly. [ABSTRACT FROM AUTHOR]

Graphene and MXenes have emerged as promising materials for gas sensing applications due to their unique properties and superior performance. This review focuses on the fabrication techniques, applications, and sensing mechanisms of graphene and MXene-based composites in gas sensing. Gas sensors are crucial in various fields, including healthcare, environmental monitoring, and industrial safety, for detecting and monitoring gases such as hydrogen sulfide (H2S), nitrogen dioxide (NO2), and ammonia (NH3). Conventional metal oxides like tin oxide (SnO2) and zinc oxide (ZnO) have been widely used, but graphene and MXenes offer enhanced sensitivity, selectivity, and response times. Graphene-based sensors can detect low concentrations of gases like H2S and NH3, while functionalization can improve their gas-specific selectivity. MXenes, a new class of two-dimensional materials, exhibit high electrical conductivity and tunable surface chemistry, making them suitable for selective and sensitive detection of various gases, including VOCs and humidity. Other materials, such as metal-organic frameworks (MOFs) and conducting polymers, have also shown potential in gas sensing applications, which may be doped into graphene and MXene layers to improve the sensitivity of the sensors. [ABSTRACT FROM AUTHOR]

The fabrication process of reduced graphene oxide depends on many factors (e.g., graphite precursor, methods of oxidation, reduction, and exfoliation) which have a significant influence on the properties of this material. Therefore, their selection is not easy due to the large number of possible combinations of these factors. To overcome this problem, we proposed to use a multivariate analysis of variance method of finding associations between the qualitative type of independent variables and the quantitative type of dependent variable. Using ANOVA, we showed that the combination (interaction) of these variables is more important than the individual influence of the variables on the fabricated rGO. Knowing how the particular variables and their combinations affect the properties of rGO, it is easier to plan the fabrication process of this material. In this paper, we analyzed the number of oxide layers and designated the most promising oxides in terms of sensor gas application. Independently, we fabricated chemiresistor sensors and studied their response to NO2 in the analyzed atmosphere. We were able to combine the experimental results with statistical analysis indicating which oxidation methods and which graphite precursors will provide the best sensitivity. [ABSTRACT FROM AUTHOR]

Currently, one of the topical directions in the field of production and application of graphene-like nanostructures is the use of renewable natural raw materials, which have unlimited resources for an economically efficient large-scale yield of a product with environmental safety. In this regard, we present the production of graphene oxide (GO) from a renewable natural raw material of plant biomass, birch activated carbon (BAC), and a comparison of the obtained physicochemical, mechanical, and electrical properties of birch activated carbon–graphene oxide (BAC–GO) and graphite–graphene oxide (G–GO) synthesized from the initial materials, BAC and graphite (G). Results obtained from this study confirm the successful oxidation of BAC, which correlates well with the physical–chemical dates of the G–GO and BAC–GO samples. Change in data after the oxidation of graphite and BAC was facilitated by the structure of the starting materials and, presumably, the location and content of functional oxygen-containing groups in the G–GO and BAC–GO chains. Based on the results, the application of a cost-effective, eco-friendly colloidal solution of nanodispersed BAC–GO from a plant biomass-based high-quality resource for producing large-scale nanostructured graphene is validated which has potential applicability in nanoelectronics, medicine, and other fields. [ABSTRACT FROM AUTHOR]

Integrating hyperthermia with conventional cancer therapies shows promise in improving treatment efficacy while mitigating their side effects. Nanotechnology-based hyperthermia, particularly using superparamagnetic iron oxide nanoparticles (SPIONs), offers a simplified solution for cancer treatment. In this study, we developed composites of SPION quantum dots (Fe3O4) with reduced graphene oxide (Fe3O4/RGO) using the coprecipitation method and investigated their potential application in magnetic hyperthermia. The size of Fe3O4 nanoparticles was controlled within the quantum dot range (≤10 nm) by varying the synthesis parameters, including reaction time as well as the concentration of ammonia and graphene oxide, where their biocompatibility was further improved with the inclusion of polyethylene glycol (PEG). These nanocomposites exhibited low cytotoxic effects on healthy cells (CHO-K1) over an incubation period of 24 h, though the inclusion of PEG enhanced their biocompatibility for longer incubation periods over 48 h. The Fe3O4/RGO composites dispersed in acidic pH buffer (pH 4.66) exhibited considerable heating effects, with the solution temperature increasing by ~10 °C within 5 min of exposure to pulsed magnetic fields, as compared to their dispersions in phosphate buffer and aqueous dimethylsulfoxide solutions. These results demonstrated the feasibility of using quantum dot Fe3O4/RGO composites for magnetic hyperthermia-based therapy to treat cancer, with further studies required to systematically optimize their magnetic properties and evaluate their efficacy for in vitro and in vivo applications. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication of ceramic Nb2O5 hollow fibers covered by a thin graphene oxide (GO) layer using the vacuum‐assisted dip‐coating process for the efficient photocatalysis degradation of methylene blue (MB) under UVC light irradiation. Pristine and GO‐coated Nb2O5 hollow fibers were evaluated for photocatalytic degradation at different initial dye concentrations and pH values. A photodegradation of 66.4% of the dye molecules was achieved using the pristine Nb2O5 hollow fibers at 57.4 ± 0.1 mg mL1, initial MB concentration of 10 mg L−1, and pH of 11. Under the same experimental conditions, the GO‐coated Nb2O5 hollow fibers degraded 100% of the MB molecules. Additionally, the GO‐coated Nb2O5 hollow fibers were successfully reused for four reaction cycles and exhibited suitable long‐term stability. Thus, the proposed ceramic Nb2O5 hollow fibers with a surface decorated by a GO layer presented suitable characteristics for use as a photocatalyst in MB degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] The creation of three dimensional (3D) structures out of two-dimensional (2D) materials while retaining their extraordinary mechanical and transport properties after processing is one of the current great challenges in materials sciences (Ruoff, 2008; Kong et al., 2019; Lin et al., 2019). Guided by density functional theory (DFT) and molecular dynamics (MD) simulations we found a successful route for a sustainable production of 3D metallic carbon materials that are synthesized from pristine 2D graphene flakes with hydrolyzed edges. The edge hydrolysis lead to strong geometrical anisotropy and self-organization in solution before processing. After processing we obtain a 3D carbon structure where 2D graphene flakes are crosslinked by carbon chains with aromatic groups at very mild annealing temperatures (∼150 °C), eliminating the constraints for achieving the in-situ preparation of conductive carbon structures. These 3D carbon structures preserve microscopic order but are macroscopically disordered, presenting physical properties of anisotropic metallic carbon with large Young modulus (E ≈ 20 GPa), and room temperature thermal (k ≈ 180 W/mK) and electrical (σ ≈ 300 kS/m) conductivities comparable to ordinary metals. [ABSTRACT FROM AUTHOR]

Composites of carbonaceous materials and the spinel metal oxides have been profoundly analyzed due to their recognized properties, including high capacity, better stability, and good cycle life. The facile synthesis of the binary composite of NiCo2O4-rGO has been done by dextrose-assisted combustion method at temperatures ranging from 300 to 500 °C in a furnace. X-ray diffraction technique has been employed to analyze properties like the crystalline nature and the cubic lattice structure of the samples. The reduction in the restacking of graphene sheets and the agglomeration of NiCo2O4 particles in the composite has been confirmed by Fourier Electron Scanning Electron Microscopy. The Energy-Dispersive X-ray Spectroscopy analysis has been done to confirm the presence of all elements and to find the elemental wt% in the composite. The strengthening of bonds between the elements present in the composite compared to their counterparts is evident from the Fourier Transform Spectroscopy. The Thermogravimetric Analysis confirms the stability of the synthesized composite to withstand higher temperatures. The electrochemical study unveils the specific capacity equal to 400 F g−1 at a 10-mV s−1 scan rate of the synthesized composite. Further, the composite material shows a promising charge–discharge rate and a lower equivalent resistance value affirming that the synthesized composite exhibits good electrochemical activities and can be utilized in energy-storing devices. [ABSTRACT FROM AUTHOR]

[Display omitted] The application of Li-S batteries on large scale is held back by the sluggish sulfur kinetics and low synthesis efficiency of sulfur host. In addition, the preparation of catalysts that promote polysulfide redox kinetics is complex and time-consuming, reducing the cost of raw materials in Li-S. Here, a universal synthetic strategy for rapid fabrication of sulfur cathode and metal compounds nanocatalysts is reported based on microwave heating of graphene. Heat-sensitive materials can achieve rapid heating due to graphene reaching 500 ℃ within 4 s via microwave irradiation. The MoP-MoS 2 /rGO catalyst demonstrated in this work was synthesized within 60 s. When used for catalysts for Li-S batteries whose graphene/sulfur cathodes were also synthesized by microwave heating, enhanced catalytic effect for sulfur redox reaction was verified via experimental and DFT theoretical results. Benefiting from fast redox reaction (MoP), smooth Li+ diffusion pathways (MoS 2), and large conductive network (rGO), the assembled Li-S battery with MoP-MoS 2 /rGO-Add@CS displays a remarkable initial specific capacity, stable lithium anode and good cycle stability (in pouch cells) using this two-pronged strategy. The work provides a practical strategy for advanced Li-S batteries toward a wide range of applications. [ABSTRACT FROM AUTHOR]

Few-layered N -doped rGO nanosheets covered with defective TiO 2- x nanoparticles form an enriched 2D/0D Schottky heterojunction through interfacial N -Ti and C-Ti bonds, serving as a bipolar cathode host for lithium-sulfur batteries with enhanced electrochemical properties. [Display omitted] The shuttling and sluggish conversion kinetics of lithium polysulfides (LiPSs) lead to poor cycling performance and low energy efficiency in lithium-sulfur batteries (LSBs). In this work, a hierarchically structured nanocomposite, synthesized through a surfactant-directed hydrothermal growth following dopamine-protected pyrolysis, serves as a bidirectional catalyst for LSBs. This nanocomposite comprises N -doped reduced graphene oxide (rGO) nanosheets anchored with uniformly distributed TiO 2- x nanoparticles via interfacial N -Ti and C-Ti bonding, resulting in the formation of abundant 2D/0D Schottky heterojunctions (rGO/TiO 2- x). Density functional theory (DFT) calculations and in situ Raman characterizations demonstrate that rGO/TiO 2- x effectively inhibits the shuttling of LiPSs with enhanced redox kinetics, achieving high utilization of the sulfur cathode and improving the overall reversibility. A high areal capacity is attained at a high sulfur loading and a low electrolyte/sulfur ratio. The initial specific capacity reaches 1010 mA h g−1 at a current density of 0.2C (1C = 1675 mA g−1), and a retention of 86.4 % is attained over 100 cycles. A light-emitting diode (LED) screen using two LSBs with rGO/TiO 2- x demonstrates their high potential for practical applications. [ABSTRACT FROM AUTHOR]