Stable Nanocomposites Research Articles

Polyfluorene-based conjugated nanocomposites with in-situ gold nanoparticles: Synthesis via rational chemical passivation and characterization of supramolecular fibrillar structures

We present a rational and innovative chemical approach for synthesizing and characterizing conjugated polymer nanocomposites as direct passivation of gold nanoparticles (AuNPs), highlighting intrinsic morphologies and distinct photophysical properties in the solid state. The pioneering synthesis of polyfluorene with thiol, LaPPS79.10, revolutionized its application as a direct passivator of AuNPs, resulting in stable nanocomposites with the capacity for storage in the dry state and subsequent redispersion in organic solvent. The presence of AuNPs with average diameters of 3.5 ± 1.3 nm induced the formation of an interconnected fibrillar supramolecular network (ribbon-like) and several microdomains in the nanocomposite (LaPPS79.10+AuNPs), correlated by XRD, TEM and SEM measurements. Characterization of the polyfluorene precursor derivative, LaPPS10, revealed bundle-like morphologies with aggregation-induced emission (AIE). Introducing thiol groups into the intermediate structure induced polymer chain organization (LaPPS79.10), leading to unique straw-like and lenticular bundle morphologies, disrupting the non-planar π-π packing and quenching the emission, a case of aggregation-caused quenching (ACQ). In LaPPS79.10+AuNPs, the proximity of the π system to the Au localized surface plasmon resonance (LSPR) resulted in high absorption, negligible self-absorption, and efficient emission quenching, as well as improved thermal resistance compared to the original polymer. The unprecedented discovery of the properties resulting from the electronic interaction between the π system of the AuNPs passivating polymer and the effects of plasmonic resonance represents a significant advance in nanoscience, opening new perspectives for exciting applications in organic photovoltaic devices and metamaterials.

Efficient and regenerative phosphate removal from wastewater using stable magnetite/magnesium iron oxide nanocomposites

Using magnetite-based nanocomposite adsorbents to remove and recycle phosphate from wastewater is crucial for controlling eutrophication and ensuring the sustainable use of phosphorus resources. However, the weak structural stability between magnetite and adsorptive nanoparticles often reduces phosphate removal efficiency in real-world applications. This instability primarily results from the loss of adsorptive nanoparticles from the magnetite surfaces, particularly when metal oxide nanoparticles are used for phosphate removal and recycling. In this study, we present a top-down approach that involves lattice locking magnesium iron oxide nanoparticles to the magnetite core, preventing magnesium loss from the magnetite surfaces. These nanocomposites exhibit exceptional performance in both phosphate recycling and removal, with a maximum adsorption capacity of 101.8 mg P·g−1. Excellent adsorption performance is also observed even in the presence of competing anions at phosphate-to-competing ion molar ratios of 1:5, 1:25, and 1:100, as well as dissolved organic matter, across a broad pH range of 4–10. The adsorbent also demonstrated minimal magnesium release during regeneration and in acidic conditions. Microscopic and spectroscopic analyses reveal that surface precipitation is the primary mechanism of phosphate removal in the magnesium-containing shells. The findings of this study address the current limitations of magnetite nanocomposites in phosphate removal, paving the way for the development of highly stable and sustainable nanocomposites for various chemical removal and recycling applications in wastewater treatment.

Catalytic activities of tannase covalently linked to amino-functionalized carbon nanotubes

Immobilized Aspergillus ficuum tannase on amino-functionalized multiwalled carbon nanotubes (A-MWCNT) was assembled through glutaraldehyde-mediated covalent coupling to produce a stable biocatalyst nanocomposite. The effective binding of tannase on the surface of A-MWCNT was evaluated and authenticated by spectroscopic signature signals and morphological differences, before and after enzyme coupling. Both free- and immobilized tannase showed optimal catalytic activities at pH 5.0 and 35 °C, with the immobilized tannase exhibiting enhanced thermostability compared to the soluble enzyme. The immobilized tannase preparation was also found to be reusable up to five cycles, with 66% of initial enzyme activity retained thereafter. The enzyme-carbon nanotube composite preparation allows for bioconversion to be accomplished in a bioreactor with a smaller footprint.

Inclusion of modified nano-magnesium hydroxide as an adjuvant flame retardant in the development of PLA/hydroxyapatite nanocomposites

For the preparation of thermal stable and flame-retardant polylactic acid (PLA) nanocomposites two new modified nano-structures including imide-carboxylated chitosan modified Mg(OH)2 (ICMH) and imide-silane functionalized hydroxyapatite nanoparticles (ISHA) were prepared. The structure, morphology, and properties of ICMH and ISHA were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field-emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA). The PLA nanocomposites were prepared via solution casting method. The results of Transmission electron microscopy (TEM) and SEM indicated a homogeneous structure for the PLA nanocomposites. The TGA results revealed that the presence of hydroxyapatite nanoparticles (HA) led to increase the thermal resistance of the PLA nanocomposites containing Mg(OH)2 (MDH). Compared to pure PLA, the Tmax value of the PLA sample containing 3 wt% of each filler (the PMH6 sample) enhanced from 364°C to 372°C. The results from the microscale combustion calorimeter (MCC) test illustrated that the key parameter values of the PLA nanocomposites were reduced, as compared to the pure PLA. The peak heat release rate (pHRR) and heat release capacity (HRC) values of PMH6 decreased 27% and 35%, respectively, as compared to the pure PLA. Also, flammability of PMH6 was reduced, as compared to the pure PLA, with UL-94 V-1 rating and LOI value 26.8%. Furthermore, the tensile strength of the mentioned sample increased from 36.04 MPa to 38.58 MPa.

Bismuth-based mesoporous nanoball carrying sorafenib for synergistic photothermal and molecularly-targeted therapy in an orthotopic hepatocellular carcinoma xenograft mouse model

Sorafenib (SOR), a multi-kinase inhibitor for advanced hepatocellular carcinoma (HCC), has limited clinical application due to severe side effects and drug resistance. To overcome these challenges, we developed a bismuth-based nanomaterial (BOS) for thermal injury-assisted continuous targeted therapy in HCC. Initially, the mesoporous nanomaterial was loaded with SOR, forming the BOS@SOR nano-carrier system for drug delivery and controlled release. Notably, compared to targeted or photothermal therapy alone, the combination therapy using this nano-carrier system significantly impaired cell proliferation and increased apoptosis. In vivo efficacy evaluations demonstrated that BOS@SOR exhibited excellent biocompatibility, confirmed through hemolysis and biochemical analyses. Additionally, BOS@SOR enhanced contrast in computed tomography, aiding in the precise identification of HCC size and location. The photothermal therapeutic properties of bismuth further contributed to the synergistic anti-tumor activity of BOS@SOR, significantly reducing tumor growth in an orthotopic xenograft HCC model. Taken together, encapsulating SOR within a bismuth-based mesoporous nanomaterial creates a multifunctional and environmentally stable nanocomposite (BOS@SOR), enhancing the therapeutic effect of SOR and presenting an effective strategy for HCC treatment.

Synthesis and Characterization of Low-Cost Zirconium Nanocomposites as Novel Adsorbents for Arsenazo III Pollutant

Removing contaminated Arsenazo III dye from contaminated effluent is a challenge and of great interest due to its hazard and environmental impact. Therefore, the biggest challenge was producing highly efficient, easy to recycle, and economically inexpensive adsorbent materials for the contaminated dye. Three chemically stable zirconium nanocomposites with unique properties were synthesized by gel-precipitation technology. The composition, chemical, and physical properties of zirconium molybdate, tungstate, and silicate nanocomposites have been extensively proven using many different and appropriate devices such as XRD, SEM–EDX, TEM, FT-IR, BET, DLS, TGA-DTA, and zeta potential. By utilizing the most effective adsorption techniques, Azo-dye was successfully bound to ZrMo-NPs, ZrW-NPs, and ZrSi-NPs composites. The uptake capacities for these composites were measured at 0.29, 0.79, and 1.61 mmol.g−1, respectively. The sorption parameters were optimized as follows: a feed solution pH of 3 for ZrMo-NPs, a pH of 2.3 for ZrW-NPs, and a pH of 2.3 for ZrSi-NPs. The stirring time was set at 30 min, the metal ion concentration was 1.64 mmol L−1, and the sorbent dose was 7.5 mg. The adsorption results agreed well with the Langmuir isotherm and the pseudo-second-order reaction models and demonstrated the endothermic nature and kinetic improvement by increasing temperatures. The three nanocomposites effectively eliminated tainted dye from lab wastewater, offering promise for their potential applications in the future.Graphical

A Nanoconfinement Strategy to Construct Co@CNTs for Lightweight and Ultra-Broadband Microwave Absorption.

The construction of stable and efficient nanocomposites with low addition and light weight has always been the goal pursued in the field of electromagnetic wave (EMW) absorption. In this study, the Co@CNTs nanocomposites with Co nanoparticles (13nm) nanoconfined in the carbon nanotube (CNT) are successfully synthesized by a simple hydrothermal method and phenolic assisted pyrolysis method. The degree of graphitization of CNTs and the microstructure of Co nanoparticles can be effectively regulated by controlling the calcination temperature. The sample calcined at 700°C can obtain excellent absorption performance at a low filling capacity of 10 wt.%: the minimum reflection loss (RL) is -41.2dB and the effective absorption bandwidth (EAB) reaches a maximum width of 14.2GHz. When the sample thickness is only 2.2mm, the EAB of <-20dB reaches 8.3GHz, which is the maximum EAB of most current Co-based absorbers. In particular, the polarization and ferromagnetic coupling behaviors are elucidated in depth with the aid of electromagnetic field simulations using the High-Frequency Structure Simulator (HFSS). This work provides a new nanoconfinement strategy for constructing the Co@CNTs nanocomposites as lightweight and ultra-broadband absorbing materials for EMW protection and EMW pollution control.

Preparation and properties of poly (ethylene-co-vinyl acetate)/boron nitride nanocomposite for energy storage devices

A simple open-mill mixing approach was employed to develop thermally and mechanically stable nanocomposites consisting of poly (ethylene- co-vinyl acetate) (EVA) as the matrix and boron nitride (BN) as a reinforcing nanofiller. The development of nanocomposites was examined by FT-IR, UV spectroscopy, XRD, TEM, TGA and DSC. The attachment of BN to EVA was confirmed by the characteristic BN band at 602 cm−1 in the FT-IR spectra. The UV measurements revealed a red shift in the nanocomposites due to nanoparticle interactions with polymer chains and the bandgap energy decreased with the nanofiller concentration. The XRD TEM analysis indicated the presence of a crystalline BN phase in EVA. Enhanced thermal stability and glass transition temperature of the polymer with the addition of BN nanoparticles were revealed from TGA and DSC, respectively. The EVA with 5% BN nanocomposite was discovered to have higher mechanical properties, electrical conductivity and lower optical bandgap energy. The tensile strength, tear resistance, impact strength and hardness of EVA increased with the inclusion of BN, whereas elongation at break was reduced. The findings of the experiments showed that the EVA/BN nanocomposites would provide excellent options for mechanically and thermally stable materials for energy storage applications.

Exploring essential oil-based bio-composites: molecular docking and in vitro analysis for oral bacterial biofilm inhibition.

Oral bacterial biofilms are the main reason for the progression of resistance to antimicrobial agents that may lead to severe conditions, including periodontitis and gingivitis. Essential oil-based nanocomposites can be a promising treatment option. We investigated cardamom, cinnamon, and clove essential oils for their potential in the treatment of oral bacterial infections using in vitro and computational tools. A detailed analysis of the drug-likeness and physicochemical properties of all constituents was performed. Molecular docking studies revealed that the binding free energy of a Carbopol 940 and eugenol complex was -2.0kcal/mol, of a Carbopol 940-anisaldehyde complex was -1.9kcal/mol, and a Carbapol 940-eugenol-anisaldehyde complex was -3.4kcal/mol. Molecular docking was performed against transcriptional regulator genes 2XCT, 1JIJ, 2Q0P, 4M81, and 3QPI. Eugenol cinnamaldehyde and cineol presented strong interaction with targets. The essential oils were analyzed against Staphylococcus aureus and Staphylococcus epidermidis isolated from the oral cavity of diabetic patients. The cinnamon and clove essential oil combination presented significant minimum inhibitory concentrations (MICs) (0.0625/0.0312mg/mL) against S. epidermidis and S. aureus (0.0156/0.0078mg/mL). In the anti-quorum sensing activity, the cinnamon and clove oil combination presented moderate inhibition (8mm) against Chromobacterium voilaceum with substantial violacein inhibition (58% ± 1.2%). Likewise, a significant biofilm inhibition was recorded in the case of S. aureus (82.1% ± 0.21%) and S. epidermidis (84.2% ± 1.3%) in combination. It was concluded that a clove and cinnamon essential oil-based formulation could be employed to prepare a stable nanocomposite, and Carbapol 940 could be used as a compatible biopolymer.

Enhanced stability of perovskite CsPbBr3 QDs via Synergetic encapsulation with ZnO nanocrystals and commercial polymer

Lead halide perovskite nanocrystals with attractive optical properties and low-cost production have emerged as a reliable and promising candidate for next-generation display applications. However, the preparation of optical devices while maintaining high performance in complex environments poses a prominent challenge. Herein, a flexible, stretchable and stable nanocomposite was fabricated through embedding CsPbBr3 QDs (PeQDs) into ZnO nanocrystals and polymer, leading to the enhancements of both stability and luminescence efficiency. This simple approach allows PeQDs own a uniform size of ∼14 nm. Optical characterization showed that the PeQDs size did not change after embedding ZnO nanocrystals, while these QDs exhibit a distinct green emission, with emission centering at 518 nm and narrow bandwidth of ∼20 nm. It was also found that the PeQDs/ZnO/EPDM nanocomposite maintained sufficient stability even after being left in an outdoor environment for 27 days, soaked in water for 60 h, and placed on a hot plate at 90 °C for 60 min. Besides, nanocomposite still maintain good luminescent properties even when stretched four times its original length. Furthermore, using this PeQDs/ZnO/EPDM nanocomposite, the synthesized white light emitting diode (WLED) exhibits a color gamut coverage rate of 129 % under standard NTSC, and 97 % under standard Rec.2020. By using this PeQDs/ZnO/EPDM encapsulation adhesive film, the absolute efficiency of solar cell can be improved by 0.23 %. This work highlights a new insight into defect passivation techniques for PeQDs by the utilization of heterogeneous structures provided by metal oxides.

Design and development of locust bean gum-endowed/Phyllanthus reticulatus anthocyanin- functionalized biogenic gold nanosystem for enhanced antioxidative and anticancer chemotherapy

Herein, the design and fabrication of an anticancer nanoplatform (LBG/PRA-NG) based on locust bean gum-stabilized nanogold and functionalized with Phyllanthus reticulatus anthocyanins was described. LBG/PRA-NG was prepared in an eco-friendly, one-pot approach at room temperature, mediated by the anthocyanins and gum as bio-reductant and stabilizer, respectively. The nanostructure was elaborately characterized by FESEM, TEM, UV–visible, DLS, Zeta potential, FTIR, XRD, TGA/DTG, and XPS analysis. Its anticancer attributes were examined based on cytotoxicity on MCF-7 and MDA-MB-231 breast cancer cell lines, as well as the generation of intracellular reactive oxygen species. The results revealed the successful formation of a homogenous and highly stable nanocomposite (LBG/PRA-NG), with quasi-spherical shape, small size (14.73 nm), Zeta potential and PDI values of −58.30 mV and 0.237, respectively. The presence of a plasmonic peak at 525 nm was indicative of AuNPs. Compared to the galactomannan and anthocyanin, LBG/PRA-NG exhibited superior antioxidative properties with IC50 values of 35.44 μg/mL against DPPH and 24.55 μg/mL against ABTS+. Notably, LBG/PRA-NG also demonstrated enhanced anticancer properties relative to LBG and anthocyanins, with IC50 values of 16.17 μg/mL and 25.06 μg/mL against MCF-7 and MDA-MB-231 cells. Meanwhile, the normal cells (HEK-293 and L929) resisted the innocuous effects of LBG/PRA-NG. Furthermore, treatment of breast cancer cells with LBG/PRA-NG drastically elevated the intracellular ROS levels. This suggested that the anticancer activity of LBG/PRA-NG may be mediated via amplification of ROS/oxidative stress-induced apoptosis. Altogether, these findings indicate the remarkable potential of LBG/PRA-NC in the development of anticancer therapy.

Highly Conductive and Long-Term Stable Phosphorene-Based Nanocomposite for Radio-Frequency Antenna Application.

In this study, an omnidirectional and high-performance free-standing monopole patch radio-frequency antenna was fabricated using a urea-functionalized phosphorene/TiO2/polypyrrole (UTP) nanocomposite. The UTP nanocomposite antenna was fabricated via ball milling of urea-functionalized phosphorene, chemical oxidative polymerization of the UTP nanocomposite, and mechanical pelletizing of the composite. Based on experiments, the proposed UTP nanocomposite-based antenna exhibited long-term stability in terms of electrical conductivity. After 12 weeks, a slight change in surface resistance was observed. The proposed antenna exhibited high radiation efficiency (78.2%) and low return loss (-36.6 dB). The results of this study suggest the potential of UTP nanocomposite antennas for applications in 5G technology.

The Use of Polysaccharide Matrices as a Basis for the Formation of Tellurium Nanoparticles with Different Morphologies.

The widening of possible areas of practical uses for zero-valent tellurium nanoparticles (Te0NPs) from biomedicine to optoelectronic and thermoelectric applications determines the actuality of the development of simple and affordable methods for their preparation. Among the existing variety of approaches to the synthesis of Te0NPs, special attention should be paid to chemical methods, and especially to "green" approaches, which are based on the use of precursors of tellurium in their powder bulk form and natural galactose-containing polysaccharides-arabinogalactan (Ar-Gal), galactomannan-(GM-dP) and κ-carrageenan (κ-CG) acting as ligands stabilizing the surface of the Te0NPs. The use of basic-reduction system "N2H4 H2O-NaOH" for preliminary activation of bulk-Te and Ar-Gal, GM-dP and κ-CG allowed us to obtain in aqueous medium a number of stable nanocomposites consisting of Te0NPs stabilized by the polysaccharides' macromolecules. By varying the precursor ratio, different morphologies of nanoparticles were obtained, ranging from spheres at a polysaccharide/Te ratio of 100:1 to rice-like at a 10:1 ratio. The type (branched, combed, or linear sulfated) of polysaccharide and its molecular weight value determined the size of the nanoparticles. Thus, the galactose-containing polysaccharides that were selected for this study may be promising renewable materials for the production of water-soluble Te0NPs with different morphology on this basis.

Multiple signal-enhanced electrochemiluminescence aptamer sensors based on carboxylated ruthenium (II) complexes for acetamiprid detection

BackgroundRapid and sensitive detection for acetamiprid, a kind of widely used neonicotinoid insecticide, is very meaningful for the development of modern agriculture and the protection of human health. Highly stable electrochemiluminescence (ECL) materials are one of the key factors in ECL sensing technology. ECL materials prepared by porous materials (e.g., MOFs) coated with chromophores have been used for ECL sensing detection, but these materials have poor stability because the chromophores escape when they are in aqueous solution. Therefore, the development of highly stable ECL materials is of great significance to improve the sensitivity of ECL sensing technology. ResultsIn this work, by combining etched metal-organic frameworks (E-UIO-66-NH2) as carrier with Tris(4,4′-dicarboxylic acid-2,2′-bipyridine)Ru(II) chloride (Ru(dcbpy)32+) as signal probe via amide bonds, highly stable nanocomposites (E-UIO-66-NH2-Ru) with excellent ECL performance were firstly prepared. Then, using MoS2 loaded with AuNPs as substrate material and co-reactant promoter, a signal off-on-off ECL aptamer sensor was prepared for sensitive detection of acetamiprid. Due to the excellent catalytic activity of E-UIO-66-NH2-Ru and MoS2@Au towards K2S2O8, the ECL signals can be enhanced by multiple signal enhancement pathways, the prepared ECL aptamer sensor could achieve sensitive detection of acetamiprid in the linear range of 10−13 to10−7 mol L−1, with the limit of detection (LOD) of 2.78ⅹ10−15 mol L−1 (S/N = 3). After the evaluation of actual sample testing, this sensing platform was proven to be an effective method for the detection of acetamiprid in food and agricultural products. Significance and noveltyThe E-UIO-66-NH2-Ru prepared by linking Ru(dcbpy)32+ to E-UIO-66-NH2 via amide bonding has very high stability. The synergistic catalytic effect of MoS2 and AuNPs enhanced the ECL signal. By exploring the sensing mechanism and evaluating the actual sample tests, the proposed signal "on-off" ECL sensing strategy was proved to be an effective and excellent ECL sensing method for sensitive and stable detection of acetamiprid.

Influence of rice straw based nanocellulose loading in sodium carboxymethyl cellulose

The goal of this research is to produce renewable and biodegradable polymers based nanocomposite films. In this study, mixture of cellulose nanocrystals and cellulose nanofibers, collectively termed as nanocellulose was extracted from agricultural waste (rice straws). Nanocellulose (NC) filled sodium carboxymethyl cellulose (CMC) films were prepared via spin coating method. Various amount of NC (0, 20, 40 wt%) were added to CMC to prepare NC filled CMC nanocomposite film. Structural, chemical, morphological and thermal properties were studied through XRD, FTIR, SEM and TGA. It was found that CMC filled NC films have higher crysatllinality along UV blocking effect with 73 % visible light transmittance. Strong H-bonding between OH-group of NC and –COOH group of CMC resulted into stable and flexible nanocomposite film. Furthermore, thermal studies confirmed that strong hydrogen bonding within CMC and NC for 40 % NC filled CMC. It resulted for phase transition of nanocomposite film through fusion at higher temperature and high mass residue as compared to bare CMC and NC.

Exploring dielectric properties and polarization relaxation processes in ionic liquid crystals with synthesized carbon and gold nanoparticles

The main goal is to study the structural and dielectric characteristics of advanced composite materials based on ionic metal alkanoates with various types of nanoparticles. The matrix Cd+2(C7H15COO)−2 formed as a result of the reaction of cadmium with the carboxylate groups of alkanoate (C7H15COO)−2 is used for the synthesis of nanoparticles. At room temperature, the matrix of the ionic crystalline material represents multilayer structure with each layer thickness of 1.8 nm. However, when heated in the temperature range from 100 °C to 180 °C, the matrix undergoes a phase transition into the liquid crystalline smectic A phase, preserved after cooling to room temperature. This transition opens up possibilities for the synthesis of carbon and gold nanoparticles. The temperature treatments of the matrix allow to control of the size and shape of nanoparticles during synthesis and create highly stable nanocomposites. The structural features and dielectric properties of these nanocomposites are studied using transmission electron microscopy, enabling to determine of the sizes of nanoparticles and their dispersion and impedance spectroscopy, respectively. Dielectric properties of nanocomposite materials were studied at different temperatures corresponding to two material phases. We carried out an analysis of the dielectric characteristics of the pure matrix in comparison with nanocomposite materials, containing carbon and gold nanoparticles to identify the role of the nanoparticles. Based on our experimental data, we proposed a model to explain the charge transfer process, taking into account relaxation processes and polarization of nanocomposite materials.

In-situ hybridization of an epoxy resin using polyurethane and MXene nanoplatelets for thermally stable nanocomposites with improved strength and toughness

A novel ternary composite system has been developed by combining MXene nanoplatelets with pre-polyurethane (PU) and an epoxy (EP) resin through in-situ polymerization and solution blending. Our approach aims to enhance the strength and toughness of the EP matrix while maintaining its thermal stability. The strong compatibility between isocyanate-terminated PU and hydroxyl-terminated MXene with the resin was demonstrated through chemical grafting and hydrogen bonding processes. In this ternary composite, significant improvements were observed, including a 32 % increase in tensile strength, a 46.4 % increase in flexural strength, and a 13.4 % increase in fracture toughness, even at very low filler contents of 0.05 wt% for MXene and 1 wt% for PU. A thorough examination of the fractured surfaces revealed the underlying mechanisms responsible for the improved strength and toughness. These mechanisms involve a transition from a brittle to a ductile fracture mode, which can be attributed to the combined effects of thermoplastic toughness, strong chemical bonding between PU and EP, and crack-anchoring and bridging effects facilitated by MXene nanoplatelets. The results presented herein are relevant to a wide range of applications in aerospace, automotive, electronics and various other industries where durability and thermomechanical performance of materials are critical.

Photocatalytic and biological efficacy of Carissa macrocarpa fruit extract-mediated one-pot synthesized ternary metal oxide dual S-scheme heterojunction

Photodegradation of organic pollutants on the surface of greenly synthesized nanomaterials under sunlight irradiation is a viable approach for water purification. Since a little attention has been paid to the green synthesis of ternary nanocomposites, therefore current work has been designed to greenly synthesized dual S-scheme heterojunction using aqueous extract of Carissa macrocarpa fruit. After successful characterization by UV-Visible spectroscopy (UV-Vis.), Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), scanning electrode microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HR-TEM), Thermogravimetric analysis (TGA), dynamic light scattering (DLS), and zeta potential analysis (ZP), Thermogravimetric analysis and X-ray photoelectron spectroscopy (XPS), the stable nanocomposite was evaluated for its catalytic potential for the photodegradation of three azo dyes, i.e., methylene blue (MB), Congo red (CR), and methyl orange (MO), under sunlight. 91 %, 97 %, and 85 % degradation with rate constant values of 2.03×10−2 min−1, 2.83×10−2 min−1, and 1.64×10−2 min−1 were observed for MB, CR, and MO, respectively, in just 120 minutes of exposure to sunlight. Effect of radical scavengers and flat band positions of NCs were evaluated to propose the mechanism and transfer of electrons and holes to decompose the dyes. The reusability of the catalyst was assessed for five consecutive cycles, which showed only a slight reduction (∼1.09%) in its activity. In addition to their photocatalytic potential, the aqueous extract and the greenly synthesized nanocomposite were also evaluated for their antibacterial potential by the disc diffusion method.

Self-optimized and stable nanocomposites via one-pot synthesis for high-temperature CO2 electrolysis in solid oxide electrolysis cells

Solid oxide electrolysis cells (SOECs) hold the promise of directly converting CO2 into CO fuels with exceptional cost-effectiveness and efficiency. However, the widespread application of SOECs is impeded by the significant lack of highly active and stable cathodes. Herein, a one-pot synthesis strategy is proposed to introduce Cu into a composite consisted of Sr2Fe1.5Mo0.5O6−δ (SFM) and Gd0.2Ce0.8O1.9 (GDC). This strategy leads to the automatic formation of hetero-structured composites, comprising double perovskite, Ruddlesden-Popper perovskite, fluorite, as well as in-situ exsolved Cu–Fe bimetals at high temperatures and operational conditions. Consequently, this approach greatly enhances CO2 adsorption capability, CO2 catalytic activity, O2−/e− conductivity, and ensures good phase compatibility with electrolyte. As results, the La0.8Sr0.2Ga0.8Mg0.2O3−δ electrolyte-supported single cell with the composite cathode achieves a high current density of 2.22 A cm−2 at 850 °C and 1.6 V, which is substantial increase of 65.7% compared to the current density achieved with traditional physically hybrid SFM-GDC cathodes. These results underscore the potential of one-pot synthesized nanocomposites as promising cathodes for CO2 electrolysis in SOECs.

Defect-induced properties of MoSi2/Nb(Ta)Si2 disilicide nanocomposites

Research on disilicide nanocomposites, as modern materials with promising technological applications, is very desirable these days. Our ab initio analysis concentrates on the C11b (tetragonal) MoSi2/C40 (hexagonal) NbSi2 or TaSi2 nanocomposites containing 12 types of interfaces formed by (110) planes in the C11b and (0001) planes in the C40 disilicide. The most stable nanocomposites are MoSi2(AC)/Nb(Ta)Si2(BAC), MoSi2(AB)/Nb(Ta)Si2(CAB) and MoSi2(AB)/Nb(Ta)Si2(ABC). The interfaces reveal positive formation energies, e.g. γIFBA = 0.63670 J.m−2 and γIFCA = 0.63727 J.m−2 in the Nb system and γIFBA = 0.57837 J.m−2 and γIFCA = 0.57802 J.m−2 in the Ta system. In the most stable C11b-MoSi2(AC)/C40-Nb(Ta)Si2(BAC) nanocomposite, the effect of the impurities (Al, Si), vacancies or their aggregates on the stability and structure is investigated. It turns out that (i) vacancies preferentially form at the Si positions in the third (first) layer of MoSi2 in the Nb (Ta) systems, utilising an energy of 2.259 eV.Va−1 (1.971 eV.Va−1); (ii) Al impurities prefer Si positions, and it is easier to introduce them into the Ta system than into the Nb one; however, this does not apply if Al is in the Mo position; (iii) Si impurities prefer Ta positions to Nb ones, and the bulk to interfacial ones; (iv) the Si-Si divacancy is the least destabilising among divacancies; and (v) Al impurities in both systems prevent the formation of Si vacancies, and the Si impurities simplify the formation of vacancies in the Nb system. As there is very little experimental information on the structure and properties of these interfaces, most of the present results are theoretical predictions which may motivate future experimental work.