Search Results (754)

Improving charge transport in the aggregated state of nanocomposites is challenging due to the large number of defects present at grain boundaries. To enhance the charge transfer and photogenerated carrier extraction of MnO_x nanofibers, a MnO_x/GO (graphene oxide) nanocomposite was prepared. The effects of GO content and bias on the optoelectronic properties were studied. Representative light sources at 405, 650, 780, 808, 980, and 1064 nm were used to examine the photoelectric signals. The results indicate that the MnO_x/GO nanocomposites have photocurrent switching behaviours from the visible region to the NIR (near-infrared) when the amount of GO added is optimised. It was also found that even with zero bias and storage of the nanocomposite sample at room temperature for over 8 years, a good photoelectric signal could still be extracted. This demonstrates that the MnO_x/GO nanocomposites present a strong built-in electric field that drives the directional motion of photogenerated carriers, avoids the photogenerated carrier recombination, and reflect a good photophysical stability. The strength of the built-in electric field is strongly affected by the component ratios of the resulting nanocomposite. The formation of the built-in electric field results from interfacial charge transfer in the nanocomposite. Modulating the charge behaviour of nanocomposites can significantly improve the physicochemical properties of materials when excited by light with different wavelengths and can be used in multidisciplinary applications. Since the recombination of photogenerated electron–hole pairs is the key bottleneck in multidisciplinary fields, this study provides a simple, low-cost method of tailoring defects at grain boundaries in the aggregated state of nanocomposites. These results can be used as a reference for multidisciplinary fields with low energy consumption. Full article

In recent years, industrial wastewater discharge containing heavy metals has increased significantly and has adversely affected both human health and the aquatic ecosystem. The increasing demand for metals in industry has prompted researchers to focus on developing effective and economical methods for removal of these metals. In this study, the removal of Ni(II) from wastewater using the Graphene oxide@Fe₃O₄@Pluronic-F68 (GO@Fe₃O₄@Pluronic-F68) nano composite as an adsorbent was investigated. The nanocomposite was characterised using a series of analytical methods, including Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis. The effects of contact time, pH, adsorbent amount, and temperature parameters on adsorption were investigated. Various adsorption isotherm models were applied to interpret the equilibrium data in aqueous solutions; the compatibility of the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models with experimental data was examined. For a kinetic model consistent with experimental data, pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models were examined. The maximum adsorption capacity was calculated as 151.5 mg·g⁻¹ in the Langmuir isotherm model. The most suitable isotherm and kinetic models were the Freundlich and pseudo-second-order kinetic models, respectively. These results demonstrate the potential of the GO@Fe₃O₄@Pluronic-F68 nanocomposite as an adsorbent offering a sustainable solution for Ni(II) removal. Full article

This study developed a water-soluble antifouling coating to protect ship hulls against corrosion and fouling without the usage of a primer. The coating retains its adhesion to the steel substrate and reduces corrosion rates compared to those for uncoated specimens. The coating’s protective properties rely on the interaction of conductive polyaniline (PAni) nanorods, magnetite (Fe₃O₄) nanoparticles, and graphene oxide (GO) sheets modified with titanium dioxide (TiO₂) nanoparticles. The PAni/Fe₃O₄ nanocomposite improves the antifouling layer’s out-of-plane conductivity, whereas GO increases its in-plane conductivity. The anisotropy in the conductivity distribution reduces the electrostatic attraction and limits primary bacterial and pathogen adsorption. TiO₂ augments the conductivity of the PAni nanorods, enabling visible light to generate H₂O₂. The latter decomposes into H₂O and O₂, rendering the coating environmentally benign. The coating acts as an effective barrier with limited permeability to the steel surface, demonstrating outstanding durability for naval steel over extended periods. Full article

This study reports the impact of a silver nanoparticles/reduced graphene oxide@titanium dioxide nanocomposite (Ag/rGO@TiO₂) on the mechanical and biocompatibility properties of poly(styrene-co-methylmethacrylate)/poly methyl methacrylate (PS-PMMA/PMMA)-based bone cement. The chemical, structural, mechanical, and thermal characteristics of Ag/rGO@TiO₂ nanocomposite-reinforced PS-PMMA bone cement ((Ag/rGO@TiO₂)/(PS-PMMA)/PMMA) were evaluated using Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nano-indentation, and electron microscopy. FT-IR, XRD, and transmission electron microscopy results confirmed the successful synthesis of the nanocomposite and the nanocomposite-incorporated bone cement. The elastic modulus (E) and hardness (H) of the ((Ag/rGO@TiO₂)/(PS-PMMA)/PMMA) bone cement were measured to be 5.09 GPa and 0.202 GPa, respectively, compared to the commercial counterparts, which exhibited E and H values of 1.7 GPa to 3.7 GPa and 0.174 GPa, respectively. Incorporating Ag/rGO@TiO₂ nanocomposites significantly enhanced the thermal properties of the bone cement. Additionally, in vitro studies demonstrated that the bone cement was non-toxic to the MG63 cell line. Full article

In this work, a glassy carbon electrode (GCE) modified with reduced graphene oxide and β-cyclodextrin (rGO/β-CD) nanocomposite was developed for the electrochemical detection of nitrofurantoin (NFT). The structural and morphological characteristics of the synthesized nanocomposite were determined using scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Moreover, the electrochemical behavior of the modified electrodes was thoroughly examined using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), with the rGO/β-CD-modified glassy carbon electrode (GCE) demonstrating superior electron transfer capability. Key experimental parameters, including scan rate, material loading, and solution pH, were systematically optimized. After optimizing the experimental conditions, the modified sensor showed excellent electrocatalytic performance and selectivity toward NFT, achieving a broad linear detection range from 0.5 to 120 μM, a low limit of detection (LOD) of 0.048 μM, and a high sensitivity of 12.1 µA µM^–1 cm^–2 using differential pulse voltammetry (DPV). Furthermore, the fabricated electrode exhibited good anti-interference ability, stability, precision, and real-time applicability for NFT detection in a wastewater sample. These results highlight the potential of the rGO/β-CD nanocomposite as a high-performance platform for electrochemical sensing applications. Full article

Background/Objectives: Although the nanocomposite of poly(L-lactic acid) with graphene oxide (PLLA-GO) shows promise for tissue engineering, its specific bioactive interactions with diverse cell lineages during early tissue regeneration remain unclear. This study comprehensively investigated the in vitro multifaceted biocompatibility of PLLA-GO using human fibroblasts (FN1 cells), murine mesenchymal stem cells (mBMSCs), and human umbilical vein endothelial cells (HUVECs). Methods: Morphological analyses were performed using optical and scanning electron microscopy, while proliferation dynamics were assessed via CFSE staining. Cell cycle progression was evaluated using flow cytometry, mitochondrial activity was examined through TMRE staining, and inflammatory cytokine profiling was performed via Cytometric Bead Array (CBA). Results: PLLA-GO exhibited primary biocompatibility across all evaluated cell lines, characterized by efficient adhesion and proliferation. However, significant cell-type-dependent modulations were observed. The FN1 cells exhibited proliferative adaptation but induced accelerated scaffold degradation, as evidenced by a substantial increase in cellular debris (5.93% control vs. 34.38% PLLA-GO; p = 0.03). mBMSCs showed a transient initial proliferative response and a significant 21.66% increase in TNF-α production (179.67 pg/mL vs. 147.68 pg/mL in control; p = 0.03). HUVECs demonstrated heightened mitochondrial sensitivity, exhibiting a 32.19% reduction in mitochondrial electrical potential (97.07% control vs. 65.82% PLLA-GO; p ≤ 0.05), alongside reductions in pro-inflammatory cytokines TNF-α (8.73%) and IL-6 (12.47%). Conclusions: The PLLA-GO processing method is crucial for its properties and subsequent cellular interactions. Therefore, rigorous and specific preclinical evaluations—considering both cellular contexts and fabrication—are indispensable to ensure the safety and therapeutic potential of PLLA-GO in tissue engineering and regenerative medicine. Full article

In this study, we synthesized anode materials based on iron oxide (Fe₂O₃), titanium dioxide (TiO₂), and reduced graphene oxide (rGO) via the electrophoretic deposition technique. The structural and morphological characteristics of electrodes were examined through various methods including SEM, XRD, Raman, and XPS. Among the investigated compositions, the three-component Fe₂O₃/TiO₂/rGO electrode displayed superior electrochemical characteristics in comparison to the binary Fe₂O₃/rGO and TiO₂/rGO electrodes. Specific capacities of 571, 683, and 729 mAh/g were achieved at 0.5 mA for the respective Fe₂O₃:TiO₂ molar ratios of 1:1, 2:1, and 3:1. The 2:1 ratio configuration offered the most promising balance between cycling stability and capacity, highlighting its potential as a high-performance anode in lithium-ion batteries. This work contributes valuable insights into the synergistic behavior of dual-transition metal oxides in composite electrode design using a low-cost and scalable method. Full article

The incorporation of commercial graphene oxide (GO) into composites offers significant improvements in mechanical, thermal, and electrical properties, making it a promising material for industrial applications. This study presents a comprehensive characterization analysis of five commercial GOs, using advanced techniques to evaluate their structural, chemical, and especially their behavior when submitted to thermal treatment. The aim is to enable the use of GO in industrial processes of particular technological importance, where its thermal stability/integrity is required, such as in polymer composites, electronic and energy storage devices, among others. Raman spectroscopy and attenuated total reflectance–Fourier-transform infrared (ATR-FTIR) spectroscopy are employed to examine the structural defects and functional groups of GOs, while X-ray diffraction (XRD) provides insight into the crystallinity and interlayer spacing. Thermogravimetric analysis (TGA) assesses the thermal stability, and X-ray photoelectron spectroscopy (XPS) offers detailed information on the surface chemistry and relevant elemental composition of GOs. Additionally, the temperature-dependent behavior of GOs is explored through temperature-dependent XRD and IR measurements to investigate the thermal expansion and functional group stability. The study highlights the critical role of oxygen-containing groups—such as epoxides, hydroxyls, and carboxyls—while variations in the type and concentration of these functional groups across commercial GOs could influence the compatibility and performance of nanocomposites. This research attempts to fill to some extent the gap in understanding how the unique properties of different commercial GOs can be strategically applied to meet specific industrial performance requirements, such as barrier properties, transport efficiency, or mechanical strength, among others. Full article

Bio-nanocomposites represent an advanced class of materials that combine the unique properties of nanomaterials with biopolymers, enhancing mechanical, electrical and thermal properties while ensuring biodegradability, biocompatibility and sustainability. These materials are gaining increasing attention, particularly in biomedical applications, due to their ability to interact with biological systems in ways that conventional materials cannot. Graphene and graphene oxide (GO), two of the most well-known nanocarbon-based materials, have garnered substantial interest in bio-nanocomposite research because of their extraordinary properties such as high surface area, excellent electrical conductivity, mechanical strength and biocompatibility. The integration of graphene-based nanomaterials within biopolymers, such as polysaccharides and proteins, forms a new class of bio-nanocomposites that can be tailored for a wide range of biological applications. This review explores the synthesis methods, properties and biotechnological applications of graphene-based bio-nanocomposites, with a particular focus on polysaccharide-based and protein-based composites. Emphasis is placed on the biotechnological potential of these materials, including drug delivery, tissue engineering, wound healing, antimicrobial activities and industrial food applications. Additionally, biodegradable polymers such as polylactic acid, hyaluronic acid and polyethylene glycol, which play a crucial role in biotechnological applications, will be discussed. Full article

In this study, a simple and efficient hydrothermal strategy was developed to modify reduced graphene oxide (rGO) with copper (II) oxide (CuO) nanoparticles by varying the weight ratio of rGO relative to CuO (rGO@CuO_1:1, rGO@CuO_1:2, and rGO@CuO_2:1). The obtained materials were further characterized using analytical tools. Photocatalytic performance was assessed using adsorption–photocatalysis experiments under a household LED light source (10 W, λ > 400 nm), and the degree of degradation of doxycycline (DOX) was evaluated using UV-Vis spectrophotometer. The highest efficiency of 100% was achieved with a DOX concentration of 70 ppm, rGO@CuO_1:1 dosage of 1 mg/mL, and pH 7 within 30 min of irradiation. The degradation kinetics followed the pseudo-first-order model (R² ~0.99) and the Langmuir adsorption isotherm, indicating that DOX on the surface is governed by a dynamic equilibrium between adsorption and degradation rates. Furthermore, efficacy was tested using real water samples, and the recyclability of the catalyst was evaluated in up to five cycles. Full article

Polycyclic aromatic hydrocarbons (PAHs) have attracted significant attention due to their severe threats to both ecological systems and human health. In this paper, a high-performance surface-enhanced Raman spectroscopy (SERS) substrate based on NCF/GO/Au@Ag nanocomposites was developed, which enabled sensitive and stable detection of PAHs. The NCF/GO/Au@Ag substrate synergistic utilizes the localized surface plasmon resonance (LSPR) effect of Au@Ag core–shell nanorods and the additional interfacial charge transfer provided by graphene oxide (GO) to exhibit extremely high sensitivity. And the three-dimensional fibrous network of nanocellulose (NCF) improved nanoparticle dispersion uniformity. Combined finite element simulations and experimental studies verified that the dual plasmonic resonances (512 nm and 772 nm) of Au@Ag nanorods optimally match 785 nm excitation, yielding an enhancement factor of 5.21 × 10⁵. GO integration enhanced Raman signals by 1.68-fold through interfacial charge transfer, while the introduction of NCF reduced the signal relative standard deviation (RSD) from 36.88% to 4.29%. The NCF/GO/Au@Ag substrate achieved a detection limit of 10 μg/L for PAHs, demonstrating exceptional sensitivity and reproducibility. Full article

Despite their outstanding thermal insulation and ultralight structure, silica aerogels suffer from inherent mechanical fragility, making the investigation of their mechanical behavior crucial for expanding their practical utility in advanced applications. To enhance their mechanical performance, this study introduces a dual-phase reinforcement strategy by anisotropically incorporating carbon nanotubes (CNTs) and graphene oxide (GO) sheets into the aerogel matrix. Using molecular dynamic simulations, we systematically investigate the tensile behavior and pore structure evolution of these hetero-structured composites. The results reveal a non-monotonic dependence of tensile strength on loading ratio, distinguishing three strain-dependent reinforcement regimes. High loading content (11.1%) significantly improves strength under low strain (0–26%), whereas low loading levels (1.8%) are more effective at preserving structural integrity under large strain (44–50%). Moderate loading (5.1%) yields balanced performance in intermediate regimes. While increasing carbon content reduces initial pore size by partially filling the framework, tensile deformation leads to interfacial debonding and the formation of larger pores due to CNT–GO hybrid structure interactions. This work elucidates a dual reinforcement mechanism—physical pore confinement and interfacial coupling—highlighting the critical role of nanostructure geometry in tuning strain-specific mechanical responses. The findings provide mechanistic insights into anisotropic nanocomposite behavior and offer guidance for designing robust porous materials for structural and functional applications. Full article

Nanotechnology has emerged as a highly focused field of research due to the unique properties of nanometric materials, particularly their large specific surface areas and excellent adsorption capabilities. This study investigated the synthesis of materials based on graphene oxide (GO) functionalized with different metal oxides (MnO₂, Fe₃O₄, CuO, NiO), with potential applications in water decontamination. The morphological, structural, and compositional properties of these nanocomposites were extensively characterized using different experimental techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM) for magnetic property evaluation. Preliminary adsorption tests were performed for the removal of pesticides and drugs from aqueous solutions. The synthesized materials demonstrated a higher affinity for selected pesticides compared to drugs. The best removal efficiencies were 98.59% for cymoxanil, 97.93% for triadimefon, 63.33% for sulfamethoxazole, and 99.59% for diclofenac. The results indicate that the functionalization of GO with metal oxides modifies the material’s structure, increasing its potential for environmental applications such as water purification. Full article

The widespread presence of pesticides—especially malathion—in aquatic environments presents a major obstacle to conventional remediation strategies, while the ongoing global energy crisis underscores the urgency of developing renewable energy sources such as hydrogen. In this context, photocatalytic water splitting emerges as a promising approach, though its practical application remains limited by poor charge carrier dynamics and insufficient visible-light utilization. Herein, we report the design and evaluation of a series of TiO₂-based ternary nanocomposites comprising commercial P25 TiO₂, reduced graphene oxide (rGO), and molybdenum disulfide (MoS₂), with MoS₂ loadings ranging from 1% to 10% by weight. The photocatalysts were fabricated via a two-step method: hydrothermal integration of rGO into P25 followed by solution-phase self-assembly of exfoliated MoS₂ nanosheets. The composites were systematically characterized using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. Photocatalytic activity was assessed through two key applications: the degradation of malathion (20 mg/L) under simulated solar irradiation and hydrogen evolution from water in the presence of sacrificial agents. Quantification was performed using UV-Vis spectroscopy, gas chromatography–mass spectrometry (GC-MS), and thermal conductivity detection (GC-TCD). Results showed that the integration of rGO significantly enhanced surface area and charge mobility, while MoS₂ served as an effective co-catalyst, promoting interfacial charge separation and acting as an active site for hydrogen evolution. Nearly complete malathion degradation (~100%) was achieved within two hours, and hydrogen production reached up to 6000 µmol g⁻¹ h⁻¹ under optimal MoS₂ loading. Notably, photocatalytic performance declined with higher MoS₂ content due to recombination effects. Overall, this work demonstrates the synergistic enhancement provided by rGO and MoS₂ in a stable P25-based system and underscores the viability of such ternary nanocomposites for addressing both environmental remediation and sustainable energy conversion challenges. Full article