MOF-on-MOF-derived FeCo@NC OER&ORR bifunctional electrocatalysts for zinc-air batteries.

Zinc-air batteries, as one of the emerging areas of interest in the quest for sustainable energy solutions, are hampered by the intrinsically sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), and still suffer from the issues of low energy density. Herein, we report a MOF-on-MOF-derived electrocatalyst, FeCo@NC-II, designed to efficiently catalyze both ORR (Ehalf = 0.907 V) and OER (Ej=10 = 1.551 V) within alkaline environments, surpassing esteemed noble metal benchmarks (Pt/C and RuO2). Systematically characterizations and density functional theory (DFT) calculations reveal that the synergistic effect of iron and cobalt bimetallic and the optimized distribution of nitrogen configuration improved the charge distribution of the catalysts, which in turn optimized the adsorption / desorption of oxygenated intermediates accelerating the reaction kinetics. While the unique leaf-like core-shell morphology and excellent pore structure of the FeCo@NC-II catalyst caused the improvement of mass transfer efficiency, electrical conductivity and stability. The core and shell of the precursor constructed through the MOF-on-MOF strategy achieved the effect of 1 + 1 > 2 in mutual cooperation. Further application to zinc-air batteries (ZABs) yielded remarkable power density (212.4 mW/cm2), long cycle (more than 150 h) stability and superior energy density (∼1060 Wh/kg Zn). This work provides a methodology and an idea for the design, synthesis and optimization of advanced bifunctional electrocatalysts.

An environmentally sustainable ultrasonic-assisted exfoliation approach to graphene and its nanocompositing with polyaniline for supercapacitor applications.

In the present work, a green high-yielding method for the preparation of graphene is introduced via ultrasonic-assisted liquid phase exfoliation (LPE) of graphite in a green solvent medium, since the common preparation method of graphene via graphite oxide is hazardous. A high concentration of 3.2 mg/ml graphene is achieved here in a comparatively short duration of 3 h ultrasonication. By using a mixed solvents strategy (acetophenone and isopropyl alcohol, 1:19 V/V), surface energy requirements needed for the exfoliation of graphite are satisfied here with acetophenone, where isopropyl alcohol further facilitated the exfoliation via non-conventional CH-π and OH-π interactions. Turbostratic graphene in high-yield (16 %) in a simple means of ultrasonic assisted LPE is the added attraction of the present procedure. The less-defective structure of graphene, its few-layered turbostratic nature, and edge functionalization of the sheets are evident from the material characterization via Raman spectroscopy, XRD, TEM-SAED, and XPS analyses. Here, we report a combination of the attractive conducting polymer polyaniline (PANI) with the as-prepared graphene for supercapacitor applications, where the PANI/graphene nanocomposites with different aniline concentrations (PANI1.125/G, PANI4.5/G, and PANI9/G) have been prepared via in-situ polymerization of aniline in the graphene dispersion. The structure and morphology of the nanocomposites are investigated using different characterization techniques which revealed that the molecular structure of the PANI is retained in the nanocomposites even with a strong interaction with graphene. FESEM and TEM images revealed the good coverage of graphene sheets with PANI that limit the volume change of PANI during the repeated charge-discharge processes. Electrochemical studies showed that PANI4.5/G has the highest specific capacitance of 126.16 mF/cm2 at a current density of 1 mA/cm2, resulting from the perfect combination of the pseudocapacitance behavior of the PANI along with the electrical double layer capacitance of graphene. A symmetric supercapacitor device is also fabricated with PANI4.5/G, which showed the highest areal capacitance of 116.38 mF/cm2 similar to that with three-electrode studies and also good cycling stability with 87 % capacitance retention in the specific capacitance after 6000 cycles. It also exhibited an energy density of 16 µWh/cm2 (0.29 Wh/kg) and a power density of 3.99 mW/cm2 (72.72 W/kg).

Efficient degradation of tetracycline antibiotics using a novel rGO/Ag/g-C3N4 photocatalyst for hospital wastewater treatment.

This study focuses on the development of an efficient photocatalyst for degrading hospital wastewater, specifically targeting the degradation of the antibiotic tetracycline (TC). We introduce a novel 2D/2D heterostructure photocatalyst composed of graphitic carbon nitride (g-CN), functionalized with silver nanoparticles (Ag NPs) and reduced graphene oxide (rGO). The primary aim is to enhance the photocatalytic performance of g-CN through the synergistic effects of Ag NPs and rGO. The rGO/Ag/g-CN nanocomposites demonstrated remarkable photocatalytic activity, achieving over 97% TC degradation within 60 min under commercial LED light irradiation. Additionally, these photocatalysts were used to remove other antibiotics, such as doxycycline hydrochloride and ofloxacin, and it was observed that the nanocomposite effectively removed these antibiotics as well. This enhanced performance is attributed to the surface plasmon resonance (SPR) effects of Ag NPs and the electron sink properties of rGO, which were confirmed through comprehensive physicochemical characterization. Various concentrations of Ag NPs and rGO were tested to optimize the nanocomposite synthesis, with optical and electrical characterizations, including photoluminescence (PL), electrochemical impedance spectroscopy (EIS), and Mott-Schottky (M-S) measurements, revealing higher electron-hole pair generation rates and carrier concentrations in the rGO/Ag/g-CN nanocomposites compared to pristine g-CN, Ag/g-CN, and rGO/g-CN. The results demonstrate the potential of the rGO/Ag/g-CN photocatalyst as a cost-effective and scalable solution for the treatment of medical pollutants in wastewater.

Optical and Chiroptical Stimuli-Responsive Chiral AgNPs@H-Leu-Poly(phenylacetylene) Nanocomposites in Water.

Dynamic macroscopically chiral nanocomposites are prepared by combining silver nanoparticles (AgNPs) and dynamic helical poly(phenylacetylene)s (PPAs) bearing pendants functionalized with amino groups. These amino groups provide the nanocomposite with the ability to disperse in water along with high stability due to the interaction between the ammonium group and the AgNP. Moreover, the equilibrium between NH3+/NH2 produces a "blinking" contact between the PPA and the AgNPs, which allows total control of the dynamic helical behavior of the polymer. The use of acidic or neutral pH allows controlling the morphology of the nanocomposite, which consists of a nanosphere that has trapped inside it a single AgNP (pH = 2) or several AgNPs (pH = 7) with ca. 30 nm of diameter. These nanocomposites combine the optical and chiroptical stimuli-responsive properties of both components, AgNPs and PPAs. Thus, the controlled aggregation of the nanocomposite produced variations in the LSPR band of the AgNPs in a reversible manner. In turn, given that the chiral coating is selective to Ba2+, the presence of this metal ion caused a helical inversion of the chiral coating of the nanocomposite detected by electronic circular dichroism. Moreover, it is possible to distinguish between three metal ions in different oxidation states, such as Ce4+, Fe3+, and Hg2+, which produce different responses of the nanocomposite when oxidizing the AgNP to Ag+.

ZnO-NaNO3 nanocomposites for solar thermal energy storage systems.

High-temperature phase change materials (PCMs) with good energy storage density and thermal conductivity are needed to utilize solar thermal energy effectively to meet industrial thermal energy demands. Composite PCMs containing a material of higher thermal conductivity and an inorganic high-temperature PCM can be explored to meet these requirements. Accordingly, a high-temperature, composite inorganic PCM (ZnO-NaNO3) with enhanced thermophysical properties was prepared, and its energy storage potential was investigated experimentally. A maximum thermal conductivity enhancement of 22.7% was achieved at 200 °C for 2 wt% ZnO-NaNO3 nanocomposite. The increase in thermal conductivity at higher temperatures may be attributed to the formation of ordered sodium nitrate layers on the nanoparticle surfaces. The increase in surface area and surface energy due to the addition of ZnO nanoparticles increased the specific heat of the nanocomposite in both the solid and liquid phases (43.5% in the liquid phase for 2 wt% ZnO-NaNO3). Thus, the addition of ZnO nanoparticles to NaNO3 increased its energy storage capacity. The addition of ZnO nanoparticles to NaNO3 did not affect the onset, peak or endset temperature during melting and freezing. Moreover, 2 wt% ZnO-NaNO3 exhibited cyclic stability even after 500 cycles and thus has potential as an energy storage medium.

Shape-Morphing in Oxide Ceramic Kirigami Nanomembranes.

Interfacial strain engineering in ferroic nanomembranes can broaden the scope of ferroic nanomembrane assembly as well as facilitate the engineering of multiferroic-based devices with enhanced functionalities. Geometrical engineering in these material systems enables the realization of 3-D architectures with unconventional physical properties. Here, 3-D multiferroic architectures are introduced by incorporating barium titanate (BaTiO3, BTO) and cobalt ferrite (CoFe2O4, CFO) bilayer nanomembranes. Using photolithography and substrate etching techniques, complex 3-D microarchitectures including helices, arcs, and kirigami-inspired frames are developed. These 3-D architectures exhibit remarkable mechanical deformation capabilities, which can be attributed to the superelastic behavior of the membranes and geometric configurations. It is also demonstrated that dynamic shape reconfiguration of these nanomembrane architectures under electron beam exposure showcases their potential as electrically actuated microgrippers and for other micromechanical applications. This research highlights the versatility and promise of multi-dimensional ferroic nanomembrane architectures in the fields of micro actuation, soft robotics, and adaptive structures, paving the way for incorporating these architectures into stimulus-responsive materials and devices.

Tensile modulus of polymer halloysite nanotubes nanocomposites assuming stress transferring through an imperfect interphase.

In this work, Hui-Shia model is developed to reveal the efficiency of a deficient interphase on the tensile modulus of polymer halloysite nanotube (HNT) nanocomposites. "Lc" as essential HNT length providing full stress transferring is defined and effective HNT size, effective HNT concentration, and efficiency of stress transferring (Q) are expressed by "Lc". Furthermore, the influences of all terms on the "Q" and nanocomposite's modulus are clarified, and also the calculations of the model are linked to the tested data of some nanocomposites. Original Hui-Shia model overpredicts the moduli, but the innovative model's predictions appropriately fit the measured data. Lc = 200 nm maximizes the sample's modulus to 2.6 GPa, but the modulus reduces to 2.11 GPa at Lc = 700 nm. Therefore, there is a reverse relation between the sample's modulus and "Lc". Q = 0.5 produces the system's modulus of 2.1 GPa, while the modulus of 2.35 GPa is achieved at Q = 1 providing a direct relation between the nanocomposite's modulus and "Q". Generally, narrow and big HNTs, along with a low "Lc", enhance the "Q", because a lower "Lc", reveals a tougher interphase improving the stress transferring.

Enhanced catalytic reduction through in situ synthesized gold nanoparticles embedded in glucosamine/alginate nanocomposites.

This study introduces a highly efficient and straightforward method for synthesizing gold nanoparticles (AuNPs) within a glucosamine/alginate (GluN/Alg) nanocomposite via an ionotropic gelation mechanism in aqueous environment. The resulting nanocomposite, AuNPs@GluN/Alg, underwent thorough characterization using UV-vis, EDX, FTIR, SEM, TEM, SAED, and XRD analyses. The spherical AuNPs exhibited uniform size with an average diameter of 10.0 nm. The nanocomposites facilitated the recyclable reduction of organic dyes, including 2-nitrophenol, 4-nitrophenol, and methyl orange, employing NaBH4 as the reducing agent. Kinetic studies further underscored the potential of this nanocomposite as a versatile catalyst with promising applications across various industrial sectors.

Efficacy of graphene nanocomposites for air disinfection in dental clinics: A randomized controlled study.

BACKGROUND: Aerosols containing disease-causing microorganisms are produced during oral diagnosis and treatment can cause secondary contamination. AIM: To investigate the use of graphene material for air disinfection in dental clinics by leveraging its adsorption and antibacterial properties. METHODS: Patients who received ultrasonic cleaning at our hospital from April 2023 to April 2024. They were randomly assigned to three groups (n = 20 each): Graphene nanocomposite material suction group (Group A), ordinary filter suction group (Group B), and no air suction device group (Group C). The air quality and air colony count in the clinic rooms were assessed before, during, and after the procedure. Additionally, bacterial colony counts were obtained from the air outlets of the suction devices and the filter screens in Groups A and B. RESULTS: Before ultrasonic cleaning, no significant differences in air quality PM2.5 and colony counts were observed among the three groups. However, significant differences in air quality PM2.5 and colony counts were noted among the three groups during ultrasonic cleaning and after ultrasonic treatment. Additionally, the number of colonies on the exhaust port of the suction device and the surface of the filter were significantly lower in Group A than in Group B (P = 0.000 and P = 0.000, respectively). CONCLUSION: Graphene nanocomposites can effectively sterilize the air in dental clinics by exerting their antimicrobial effects and may be used to reduce secondary pollution.

Superior remedy colon cancer HCT-116 cells via new chitosan Schiff base nanocomposites: Synthesis and characterization.

Cancer is a serious worldwide health problem and colon cancer is the major cancer public prevailing form. The innovative pharmaceuticals with great cancer efficacy are metal nanoparticles. Therefore, the present study relies on developing chitosan Schiff base nanocomposites and investigating their antitumor ability against human colon carcinoma (HCT-116 cell line) using the MTT method. Thus, chitosan (CS) is modified with 9-ethyl-3-carbazolecarboxaldehyde (ECCA) in the absence or presence of the biomedical crosslinker poly(ethylene glycol) diglycidyl ether (PEGDGE) under microwave irradiation to afford CS-Schiff bases CS-SB-I and CS-SB-II, respectively. The assembly method is applied to formulate CS-Schiff base (Ag, Au and ZnO) nanocomposites. These new CS-Schiff bases and their nanocomposites are characterized by utilizing elemental analysis, FTIR, TGA, XRD, SEM, TEM and EDX. Cytotoxicity test showed that CS-SB-I (IC50 112.10 ± 4.23 µg/mL) and CS-SB-II (IC50 98.54 ± 4.09 µg/mL) inhibit the growth of HCT-116 more effectively than chitosan (IC50 181.38 ± 6.54 µg/mL). Additionally, CS-Schiff base nanocomposites revealed superior anticancer efficiency which displayed the lowest IC50 values CS-SB-I-Ag (IC50 10.99 ± 0.37 µg/mL), CS-SB-II-Ag (IC50 12.79 ± 0.49 µg/mL), CS-SB-I-Au (IC50 14.96 ± 0.51 µg/mL), CS-SB-II-Au (IC50 26.72 ± 1.57 µg/mL), CS-SB-I-ZnO (IC50 22.79 ± 1.28 µg/mL) and CS-SB-II-ZnO (IC50 22.24 ± 1.34 µg/mL). The findings demonstrated that CS-Schiff base nanocomposites are promising agents for the HCT-116 cell therapeutic.

Synergistic effects of thermally reduced graphene oxide/zinc oxide composite material on microbial infection for wound healing applications.

Infections originating from pathogenic microorganisms can significantly impede the natural wound-healing process. To address this obstacle, innovative bio-active nanomaterials have been developed to enhance antibacterial capabilities. This study focuses on the preparation of nanocomposites from thermally reduced graphene oxide and zinc oxide (TRGO/ZnO). The hydrothermal method was employed to synthesize these nanocomposites, and their physicochemical properties were comprehensively characterized using X-ray diffraction analysis (XRD), High-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FT-IR), Raman spectroscopy, UV-vis, and field-emission scanning electron microscopy (FE-SEM) techniques. Subsequently, the potential of TRGO/ZnO nanocomposites as bio-active materials against wound infection-causing bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, was evaluated. Furthermore, the investigated samples show disrupted bacterial biofilm formation. A reactive oxygen species (ROS) assay was conducted to investigate the mechanism of nanocomposite inhibition against bacteria and for further in-vivo determination of antimicrobial activity. The MTT assay was performed to ensure the safety and biocompatibility of nanocomposite. The results suggest that TRGO/ZnO nanocomposites have the potential to serve as effective bio-active nanomaterials for combating pathogenic microorganisms present in wounds.

Insights into Thermal Conductivity at the MOF-Polymer Interface.

Understanding the thermal conductivity in metal-organic framework (MOF)-polymer composites is crucial for optimizing their performance in applications involving heat transfer. In this work, several UiO66-polymer composites (where the polymer is either PEG, PVDF, PS, PIM-1, PP, or PMMA) are examined using molecular simulations. Our contribution highlights the interface's impact on thermal conductivity, observing an overall increasing trend attributable to the synergistic effect of MOF enhancing polymer thermal conductivity. Flexible polymers such as PEG and PVDF exhibit increased compatibility with the MOF, facilitating their integration with the MOF lattice. However, this integration leads to a moderated enhancement in thermal conductivity compared to polymers that remain separate from the MOF structure, such as PS or PP. This effect can be attributed to alterations in phonon transport pathways and shifts in interfacial interactions between the polymer and MOF. Specifically, the infiltration of the polymer like PEG and PVDF into the MOF disrupted the MOF's ordered network, introducing defects or barriers that hindered phonon propagation. In contrast, nonpolar and rigid polymers like PP, PMMA, PS, and PIM-1 exhibited greater improvements in thermal conductivity when combined with MOFs compared to the flexible polymers PVDF and PEG. Most notably, our analysis identifies a critical interface region within approximately 30-50 Å that profoundly influences thermal conductivity. The interface region, as indicated by the density profile and radius of gyration, is notably shorter but plays a pivotal role in modulating the thermal properties. The sensitivity of the system to these interface characteristics underscores the crucial role of this particular interface area in dictating the thermal conductivity. Our findings emphasize the sensitivity of thermal conductivity in polymer matrices to interface characteristics and highlight the critical role of a specific interface region in modulating thermal properties.

Fe(OH)3/Ti3C2Tx nanocomposites for enhanced ammonia gas sensor at room temperature.

Two-dimensional material (2D material) MXene has great application potential in gas sensors because of its excellent controllable performance and vast specific surface area. In this study, we used a straightforward in-situ electrostatic self-assembly technique to create Fe(OH)3/Ti3C2Tx nanocomposites, which were then used to fabricate gas sensors for ammonia detection at room temperature (25 ℃). Several characterization methods were performed aimed at determining the surface appearance and construction of the nanocomposites, and the sensing characteristics and mechanism were also systematically examined. The findings demonstrate the effective incorporation of amorphous Fe(OH)3 nanoparticles on the surface of Ti3C2Tx. Additionally the nanocomposites of Fe(OH)3/Ti3C2Tx have considerably higher specific surface area than pure Ti3C2Tx, hence offering more active NH3 adsorption sites. The response of the sensor to 100 ppm NH3 was 48.6% at room temperature, which was 9.3 times more higher than that of pure Ti3C2Tx. The sensors also have the advantages of long-term stability (33 days), low NH3 detection limit (500 ppb), and rapid recovery time (85 s) and response times (78 s). It is anticipated that this work will be helpful for developing the new generation of wearable ammonia sensors at room temperature.

Surface Modification of Gold Nanorods: Multifunctional Strategies and Application Prospects.

Gold nanorods (AuNRs), as an important type of gold nanomaterials, have attracted much attention in the nano field. Compared with gold nanoparticls, AuNRs have broader application potential due to their tunable localized surface plasmon resonance properties and anisotropic shapes. Yet, conventional synthesis methods using surfactants have limited the use of AuNRs in a variety of fields such as biomedical applications, plasma-enhanced fluorescence, optics and optoelectronic devices. To solve this problem and improve the stability and biocompatibility of AuNRs, researchers in recent years have used surface modification and functionalization to modify AuNRs, among which the introduction of organic ligands to prepare organic/gold hybrid nanorods has become an effective strategy. Organic materials have better toughness and easy processing, and by introducing organic ligands into the surface of AuNRs, the molecular-level composite of organic and inorganic materials can be realized, thus obtaining hybrid nanorods with excellent properties. This paper reviews the research progress of hybrid nanocomposites, and introduces the synthesis methods of AuNRs and the development of surface ligand modification, then summaries the applications of a wide variety of ligands. Also, the advantages and disadvantages of different ligands and their roles in further self-assembly processes are discussed.

Bright Nanocomposites based on Quantum Dot-Initiated Photocatalysis.

Integrating quantum dots (QDs) into polymer matrix to form nanocomposites without compromising the QD photoluminescence (PL) is crucial to emerging QD light-emitting and solar energy conversion fields. However, the most widely-used bulk polymerization technique, where monomers serve as the QD solvent, usually leads to QD PL quenching caused by radical initiators. Here we demonstrate high-brightness nanocomposites with near-unity PL quantum yield (QY), through a novel QDs-catalyzed (-initiated) bulk polymerization without using any radical initiators. Different from previous reports where QDs were designed as photo-sensitizers/catalysts (always with cocatalysts) and hence non-emissive in catalytic conditions, our QDs combine high brightness with highly effective catalysis, a combination that was previously considered to be hardly possible. In our case, apart from emitting light (at a large probability), the photoexcited QDs act as 'overall reaction' catalysts by simultaneously employing photoexcited electrons and holes to produce active radicals without the need of any sacrificial agents. These active radicals, though with a small amount, are sufficient to initiate effective chain reaction-dominated bulk polymerization, eliminating the requirement of extra radical initiators. This study provides new insights for understanding and development of QDs for energy applications.

Nanocomposite Hydrogels from Nanodiamonds and a Self-Assembling Tripeptide.

We report the successful assembly of a tripeptide in the presence of nanodiamonds (NDs) into nanocomposite hydrogels. The presence of NDs does not hinder peptide self-assembly and gelation, whilst improving the viscoelastic properties of the hydrogels. Gelation kinetics are not affected by NDs, while the elastic moduli of the peptide hydrogels are significantly increased by the NDs. Increased resistance of the gels against applied stress can also be attained depending on the amount of NDs loaded in the nanocomposite. Raman micro-spectroscopy and TEM confirmed the presence of NDs on the surface, and not in the interior, of peptide nanofibers. Peptide-ND non-covalent interactions are also probed by Raman and Fourier-transformed infrared spectroscopies. Overall, this work enables the embedding of NDs into nanocomposite hydrogels formed through the self-assembly of a simple tripeptide at physiological pH, and it provides key insights to open the way for their future applications in biomaterials, for instance exploiting their luminescence and near-infrared responsiveness.

Facile Synthesis of Aptamer-Functionalized Polydopamine-Coated Magnetic Graphene Oxide Nanocomposites for Highly Efficient Purification of His-Tagged Proteins.

Recombinant proteins hold significant importance in numerous disciplines. As the demand for expressing and purifying these proteins grows, the scientific community is in dire need of a simple yet versatile methodology that can efficiently purify these proteins. Aptamers as synthetic nucleic acid-based ligands with high affinity have shown promise in this regard, as they can capture targets through molecular recognition. In this study, novel aptamer-functionalized polydopamine-coated magnetic graphene oxide nanocomposites were facilely prepared, achieving an impressive average aptamer coverage density (45 nmol/mg). These nanocomposites exhibited a uniform structure and robust magnetic responsiveness. The findings indicated that they possess several advantages, such as rapid adsorption, substantial capacity (171.4 mg/g), and excellent reusability. Notably, due to the inherent properties of nucleic acids, the immobilized aptamer-magnetic beads can be utilized repeatedly with high purification efficiency. Finally, the nanocomposites were further employed to purify His-tagged proteins from actual samples. Remarkably, they were able to selectively and efficiently isolate His-tagged retinoid X receptor alpha protein from complex Escherichia coli lysate. The purified His-tagged retinoid X receptor alpha protein was analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This confirmed the efficacy of developed nanocomposites, reinforcing their vast potential for purification of His-tagged recombinant proteins.

Efficient water purification: CuO-enhanced biochar from banana peels for removing Congo red dye.

Treating dye-containing wastewater poses numerous challenges due to its high chemical complexity and its persistent nature. Thus, the present study aims to synthesize biochar derived from banana peel (BC) and its nanocomposites with copper oxide nanoparticles (CuOx/BC1-x) for the purpose of adsorptive removing Congo red (CR) dye from water. Several analytical methods were utilized to describe the physicochemical features of the CuOx/BC1-x nanocomposites. It was found that the crystallinity of the nanocomposites gradually improved, while the specific surface area and the surface electronegativity were reduced with increasing x value. The effects of x values (0-0.5), interaction time (10-120 min), adsorbent dose (0.01-0.05 g), initial CR concentration (20-200 mg/L), and the solution temperature (20-60 °C) were evaluated on CR removal. The obtained results revealed that the CuO0.5/BC0.5 nanocomposite showed the highest adsorption efficiency with a maximum adsorption capacity of 233.6 mgg-1. Analysis of the equilibrium experimental data revealed that the Langmuir and the pseudo-2nd-order models were the most proper to describe the current adsorption process. Moreover, the thermodynamics studies demonstrated that the adsorption process was spontaneous, endothermic, and random.

Enhancing Mechanical Properties of Graphene/Aluminum Nanocomposites via Microstructure Design Using Molecular Dynamics Simulations.

This study explores the mechanical properties of graphene/aluminum (Gr/Al) nanocomposites through nanoindentation testing performed via molecular dynamics simulations in a large-scale atomic/molecular massively parallel simulator (LAMMPS). The simulation model was initially subjected to energy minimization at 300 K, followed by relaxation for 50 ps under the NPT ensemble, wherein the number of atoms (N), simulation temperature (T), and pressure (P) were conserved. After the model was fully relaxed, loading and unloading simulations were performed. This study focused on the effects of the Gr arrangement with a brick-and-mortar structure and incorporation of high-entropy alloy (HEA) coatings on mechanical properties. The findings revealed that Gr sheets (GSs) significantly impeded dislocation propagation, preventing the dislocation network from penetrating the Gr layer within the plastic zone. However, interactions between dislocations and GSs in the Gr/Al nanocomposites resulted in reduced hardness compared with that of pure aluminum. After modifying the arrangement of GSs and introducing HEA (FeNiCrCoAl) coatings, the elastic modulus and hardness of the Gr/Al nanocomposites were 83 and 9.5 GPa, respectively, representing increases of 21.5% and 17.3% compared with those of pure aluminum. This study demonstrates that vertically oriented GSs in combination with HEA coatings at a mass fraction of 3.4% significantly enhance the mechanical properties of the Gr/Al nanocomposites.

Investigation of MO Adsorption Kinetics and Photocatalytic Degradation Utilizing Hollow Fibers of Cu-CuO/TiO2 Nanocomposite.

This comprehensive study explores the kinetics of adsorption and its photocatalytic degradation of methyl orange (MO) using an advanced copper-decorated photocatalyst in the form of hollow fibers (HFs). Designed to boost both adsorption capacity and photocatalytic activity, the photocatalyst was tested in batch experiments to efficiently remove MO from aqueous solutions. Various isotherm models, including Langmuir, Freundlich, Sips, Temkin, and Dubinin-Radushkevich, along with kinetic models like pseudo-first and pseudo-second order, Elovich, Bangham, and Weber-Morris, were utilized to assess adsorption capacity and kinetics at varying initial concentrations. The results indicated a favorable MO physisorption on the nanocomposite photocatalyst under specific conditions. Further analysis of photocatalytic degradation under UV exposure revealed that the material maintained high degradation efficiency and stability across different MO concentrations. Through the facilitation of reactive oxygen species generation, oxygen played a crucial role in enhancing photocatalytic performance, while the degradation process following the Langmuir-Hinshelwood model. The study also confirmed the robustness and sustained activity of the nanocomposite photocatalyst, which could be regenerated and reused over five successive cycles, maintaining 92% of their initial performance at concentrations up to 15 mg/L. Overall, this effective nanocomposite photocatalyst structured in the form of HF shows great promise for effectively removing organic pollutants through combined adsorption and photocatalysis, offering valuable potential in wastewater treatment and environmental remediation.