Characteristics Of Nanostructures Research Articles

Decorated palladium nanoparticles over chitosan-agarose encapsulated Fe3O4 microspheres: Investigation of its catalytic efficiency in the Suzuki-Miaura coupling reactions

The enhanced properties of heterogeneous catalysts have led to significant interest in recent years, particularly in composite materials that incorporate organic-inorganic systems. In this particular study, a series of steps were undertaken to synthesize Fe3O4 microspheres, which were subsequently coated with chitosan and agarose. Finally, palladium nanoparticles were immobilized onto the surface of the microspheres, resulting in the formation of Fe3O4 MPs@CS-Agar/Pd NPs. To evaluate the material, advanced analytical techniques such as FT-IR, FESEM-EDS, ICP-OES, TEM, XRD, and VSM were utilized to determine its structural and physicochemical characteristics. The results shown that the Pd nanoparticles were formed in nanometer-sized particles, exhibiting a quasi-spherical shape with an average diameter ranging from 20–40 nm. Notably, the Fe3O4 MPs@CS-Agar/Pd NPs exhibited remarkable catalytic activity in Suzuki-Miyaura reaction. Importantly, the nanocatalyst could be reused up to 8 times without any decline in its activity. The exceptional catalytic performance of the Fe3O4 MPs@CS-Agar/Pd NPs in these reactions can be attributed to the distinctive nanostructure characteristics it possesses.

Simultaneous tartrazine-tetracycline removal and hydrogen production in the hybrid electrocoagulation-photocatalytic process using g-C3N4/TiNTAs

This study aimed to investigate the removal of tartrazine dye & tetracycline antibiotic and hydrogen (H2) production simultaneously through the hybrid electrocoagulation-photocatalytic process using g-C3N4/TiO2 nanotube arrays (TiNTAs) nanocomposite. The g-C3N4/TiNTAs was used as the photocatalyst. The melamine as the precursor of g-C3N4 was varied to obtain the optimal loading on the removal of tartrazine dye & tetracycline antibiotic and hydrogen (H2) production simultaneously. The integrated acrylic photoreactor was equipped with two 250-W mercury lamps. The nanotubular morphology of TiNTAs and nanostructure features of g-C3N4/TiNTAs were examined using FESEM/EDX and HR-TEM/SAED. The XRD patterns indicated the composition of TiNTAs, confirming the presence of anatase and rutile crystalline phases. UV-Vis DRS also showed a redshift in the composite absorbance and a reduced bandgap with g-C3N4 introduction. The results showed that when tartrazine and tetracycline were treated simultaneously, tartrazine was more dominantly degraded compared to tetracycline. In mixed pollutant system condition, the H2 production increased by 17.0% and 41.1% compared to single pollutant system of tartrazine and tetracycline, respectively. The photocatalyst used in the hybrid process was the g-C3N4/TiNTAs (3 g) which provide the optimum H2 production.

Phytosomes Nanocarrier with Insight Towards the Future in Cancer Therapy: A Mini-Review.

Cancer is classified as having one of the highest mortality rates on a global scale, presenting a significant challenge in its treatment, especially when conventional chemotherapy methodologies are used. Conversely, there is a growing interest in utilizing herbal medicine as an alternative to the treatment of cancer because of its lack of adverse effects compared to contemporary medical strategies. The incorporation of nanotechnology into therapy has attracted attention owing to its efficacy in the treatment of various illnesses. Phytosomes play a crucial role in the treatment of cancer by enhancing the characteristics of drugs and nanostructures within carriers to enable targeted drug delivery. The establishment of chemical bonds between phospholipid molecules and bioactive compounds from plants ensures the stability of phytosomes, thus establishing them as an innovative mechanism for drug delivery systems that transport plant-derived constituents to specific areas. This mini-overview discusses the potential phytosome complexes, uses, drawbacks, patents, challenges, and prospects of phytosomes in cancer treatment. Thus, numerous phytosomal formulations incorporating plant-derived components have exhibited promising anticancer properties, with several formulations currently undergoing clinical trials.

Tailoring the Structure, Optical and Shielding Characteristics of ZnMn2O4 Nanostructures through Sn-Doping

The current study aims to tailor the structure, optical and shielding characteristics of ZnMn2O4 nanostructures through Sn-doping. ZnMn2−xSnxO4 nanostructures were synthesized by the sol-gel technique. The sample containing 5% Sn exhibits the highest level of absorbance. ZnMn2−xSnxO4 system exhibits a maximum optical energy gap value of 2.55 eV when doped with 10% Sn, and a minimum optical energy gap value of 2.23 eV when doped with 5% Sn. The refractive index values of the samples containing 5 and 10% Sn are the highest in comparison to the other samples. The values of the non-linear optical parameters became maximum as x = 0.05. The radiation shielding constants were computed by Phy-X/PSD software. The half value length and tenth value length values reduced as ZnMn2O4 doped with Sn, implying that doped samples have better shielding capabilities than undoped ZnMn2O4. When compared to doped samples, ZnMn2O4 has the highest fast neutron removal cross-section value. ZnMn2-xSnxO4 samples demonstrate a greater rate of absorption for photons with lower energy as opposed to those with higher energy.

EFFECT OF NIOBIUM DOPANT CONCENTRATION ON ZNO NANOSTRUCTURES ON SI POROUS SUBSTRATE

Zinc oxide (ZnO) nanostructures have gained popularity in sensor technology due to their unique properties and facile device integration. However, the intrinsic optical and electrical properties of ZnO are suboptimal for direct industrial applications, necessitating enhancements through doping. This study investigates the impact of niobium (Nb) doping concentrations on the physical, optical, and electrical characteristics of ZnO nanostructures. FESEM analyses indicate successful deposition of ZnO on silicon nanoparticles substrates, with nanostructure sizes peaking at 88 nm and 115 nm for 6% and 8% Nb dopant concentrations, respectively. XRD results suggest that the structural integrity of the nanostructures is maintained up to a 10% doping level, with an optimal concentration at 6%. UV-Vis spectroscopy shows a shift in the absorption peak into the visible range and a decrease in maximum reflectivity from 47.5990% at 2% doping to 40.9205% at 6% doping, indicating enhanced light absorption suitable for optoelectronic applications. Electrical measurements reveal that a 6% Nb dopant concentration yields the lowest resistivity and highest conductivity among the tested samples. These findings underscore the potential of Nb-doped ZnO nanostructures in improving the performance of optoelectronic devices through tailored doping strategies.

Tailoring Plasmonic Fields with Shape-Controlled Single-Crystal Gold Metasurfaces.

Geometry and crystallinity play a critical role in the wavelength-dependent optical responses and plasmonic local near-field distributions of metallic nanostructures. Nevertheless, the ability to tailor the shape and position of crystalline metal surface nanostructures has remained a challenge that limits control of their enhanced local fields and represents a barrier to harnessing their individual and collective responses. Here, we describe a solution deposition method in the presence of anionic additives, which yields shape-controlled, single-crystal plasmonic gold nanostructures on Ag(100) and Au(100) substrates. Use of SO42- ions yields smooth Au(111)-faceted square pyramids with large plasmonic Raman enhancements. Halide additives produce textured hillocks comprising edge- and screw-type dislocations (Cl-), or platelets with large-area Au(100) terraces and (110) step edges (Br-), while SO42- and Br- additive combinations provide Au(110)-faceted square pyramids. With lithographic patterning, this chemistry yields metal deposition with precise geometry and location control to provide single-crystal, plasmonic gold metasurfaces with tailored optical response. The appropriately designed metasurfaces can then generate large Raman scattering enhancements, far greater than high density gold square pyramids with random surface disposition. Shape-controlled single-crystal plasmonic metasurfaces will thus offer opportunities to tune the characteristics of nanostructures, providing enhanced optical, photocatalytic, and sensory response.

Gold Nanostructures for an Effective Bone Cancer Therapy: Numerical Simulation and Experimental Investigation

AbstractGold nanostructures play a crucial role in medical applications, harnessing size and shape‐dependent properties. A prominent area of research is cancer treatment through the photothermal approach. Here, numerical simulation is explored to study the impact of gold nanostructure size, shape, and laser parameters on spatiotemporal temperature patterns during photothermal therapy (PTT). Spherical, rod, star, bipyramid, and cubic nanostructures in small, medium, and large sizes underwent 150 s of laser irradiation. COMSOL software, incorporating bioheat physics, precisely gauged thermal variations. The structural characteristics notably influence the temperature profiles, with medium‐sized rod, star, and bipyramid gold nanoparticles exhibiting superior thermal properties. Experimental validation of simulations focuses on the optimal nanostructure, synthesizing through the seed growth method. Transmission electron microscopy, UV‐visible spectroscopy, and X‐ray diffraction analysis confirm its proposed characteristics. Results demonstrate a robust correlation between experimental and simulation parameters, affirming precision. Findings showcase photothermal properties in line with theoretical predictions. The aim of this study is to determine the optimal gold nanostructure for bone cancer treatment using PTT, addressing the challenges presented by the dense and resilient nature of bone tissue and deep tumor locations. By utilizing multi‐physical modeling and simulations facilitated by COMSOL software, a novel method for pre‐clinical estimation is introduced. This research provides insights into each nanoparticle‐based PTT process prior to ex vivo and in vivo studies, offering a comprehensive understanding of the interplay between nanostructure characteristics and PTT outcomes. The approach contributes to advancing the field of cancer treatment by enhancing the predictability and effectiveness of nanoparticle‐mediated PTT.

Effects of surface nanostructure and wettability on CO2 nucleation boiling: A molecular dynamics study

Nanostructured tubes hold great potential for enhancing heat transfer in refrigeration/heat pump systems. Therefore, it is essential to study the effects of nanostructured surface characteristics on refrigerant boiling heat transfer. In this paper, the nucleation boiling behavior of CO2 on the nanostructured surface is simulated using molecular dynamics. The effect mechanism of nanostructure size and surface wettability on CO2 bubbles nucleation and growth is investigated. At first, the nucleation boiling processes of both smooth surfaces and nanostructured surfaces featuring three different wide grooves are simulated. The results show that the local thermal aggregation effect is the key for nanostructures to promote CO2 bubble nucleation. The bubble nucleation efficiency is highest on the nanostructured surface with 5 ​nm wide groove. Then, based on a 5 ​nm wide nanostructured wall surface, the wettability effect on nucleation boiling is investigated by adjusting the potential energy factor α. The results show that the hydrophilic walls enhance the solid-liquid heat transfer and the collision of atoms within the liquid, resulting in boiling heat transfer capacity improvement between CO2 and the walls. The average temperature, average heat flux and critical heat flux in the liquid phase are also improved. A significant temperature gradient between the layers of CO2 liquid is noted on hydrophilic wall, where intermolecular forces and molecular advection dominate the heat transfer mechanism. In contrast, on hydrophobic wall, intermolecular forces dominate the heat transfer process.

Monitoring ocular disease via optical nanostructures potentially applicable to corneal contact lens products

Ocular diseases can cause vision problems or even blindness if they are not detected early. Some ocular diseases generate irregular physical changes in the eye; therefore, reliable diagnostic technology for continuous monitoring of the eye is an unmet clinical need. In this study, a pulsed laser (Nd:YAG) was used to create optical nanostructures on a hydrogel-based commercial contact lens. Simulations were used to determine the spacing of the nanostructures, which were then produced and tested on the lens in ambient humidity and fully hydrated environments. The nanostructures produced a 4° diffraction angle difference in response to the environmental changes. Vision obstruction was considered while designing the nanostructure features on the lens. The curved nanostructures exhibited a series of visible rainbow colors with an average range of 8° under normal room light. A spherical surface was also used to simulate the human eye, and application of a force (curvature change) caused the nanostructure spacing to change, influencing the visible color of the contact lenses. A smartphone camera application was used to measure the progress of ocular diseases by analyzing the RGB color values of the visible color. The nanostructures were also responsive to K+ ion variations in artificial tear fluids, with a 12 mmol L−1 sensitivity, which may allow the detection of ocular ionic strength changes.

Electric-field-controlled electronic structures and quantum transport in monolayer InSe nanoribbons

Electronic structures and quantum transport properties of the monolayer InSe nanoribbons are studied by adopting the tight-binding model in combination with the lattice Green function method. Besides the normal bulk and edge electronic states, a unique electronic state dubbed as edge-surface is found in the InSe nanoribbon with zigzag edge type. In contrast to the zigzag InSe nanoribbon, a singular electronic state termed as bulk-surface is observed along with the normal bulk and edge electronic states in the armchair InSe nanoribbons. Moreover, the band gap, the transversal electron probability distributions in the two sublayers, and the electronic state of the topmost valence subband can be manipulated by adding a perpendicular electric field to the InSe nanoribbon. Further study shows that the charge conductance of the two-terminal monolayer InSe nanoribbons can be switched on or off by varying the electric field strength. In addition, the transport of the bulk electronic state is delicate to even a weak disorder strength, however, that of the edge and edge-surface electronic states shows a strong robustness against to the disorders. These findings may be helpful to understand the electronic characteristics of the InSe nanostructures and broaden their potential applications in two-dimensional nanoelectronic devices as well.

Facile synthesis of porous ZnCo2O4 micro–flower decorated with SWCNTs toward superior lithium storage performance

Binary metal oxides ZnM2O4 (A = Co, Fe, Mn) with spinel structures have been widely studied for their high theoretical specific capacity, relatively low cost, controllable morphology and synergistic effect between metal oxides with different charging and discharging mechanisms. However, the electrochemical properties are seriously affected by the huge volume change during cycles and poor electronic conductivity. In this work, porous ZnCo2O4 micro–flowers self–assembled from nano–sheets are successfully prepared by a simple solvothermal method followed by a heat treatment process without the aid of any soft/hard templates, and the resulting ZnCo2O4 active material is further decorated with SWCNTs. The phase composition, morphology characteristic, specific surface area, pore size distribution, elemental valence state and other information of the as–prepared samples are analyzed by relevant techniques such as XRD, FTIR, FESEM, (HR)TEM, TGA, Raman, N2 adsorption/desorption measurement and XPS. As anode materials in Li–ion batteries, the ZnCo2O4/SWCNTs product exhibits high charge/discharge specific capacity, excellent cycling stability and remarkable rate capability. Excellent electrochemical performance benefits from the special micro–/nano–structure characteristics of the as–synthesized ZnCo2O4/SWCNTs electrode material and good dynamic characteristics during cycling.

Impacts of Fuel Stage Ratio on the Morphological and Nanostructural Characteristics of Soot Emissions from a Twin Annular Premixing Swirler Combustor.

Soot particles emitted from aircraft engines constitute a major anthropogenic source of pollution in the vicinity of airports and at cruising altitudes. This emission poses a significant threat to human health and may alter the global climate. Understanding the characteristics of soot particles, particularly those generated from Twin Annular Premixing Swirler (TAPS) combustors, a mainstream combustor in civil aviation engines, is crucial for aviation environmental protection. In this study, a comprehensive characterization of soot particles emitted from TAPS combustors was conducted using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The morphology and nanostructure of soot particles were examined across three distinct fuel stage ratios (FSR), at 10%, 15%, and 20%. The SEM analysis of soot particle morphology revealed that coated particles constitute over 90% of the total particle sample, with coating content increasing proportionally to the fuel stage ratio. The results obtained from HRTEM indicated that average primary particle sizes increase with the fuel stage ratio. The results of HRTEM and Raman spectroscopy suggest that the nanostructure of soot particles becomes more ordered and graphitized with an increasing fuel stage ratio, resulting in lower oxidation activity. Specifically, soot fringe length increased with the fuel stage ratio, while soot fringe tortuosity and separation distance decreased. In addition, there is a prevalent occurrence of defects in the graphitic lattice structure of soot particles, suggesting a high degree of elemental carbon disorder.

A highly sensitivity electrochemistry biosensor for E. coli DNA detection based on hollow and porous dCuO@rGO composite

A highly sensitive DNA (deoxyribonucleic acid) sensor was prepared by using dCuO particles (derived from HKUST-1), electrochemical-reduced graphene oxide (rGO) and chitosan (CS) composite modified glassy carbon electrode (CS/dCuO@rGO/GCE). The morphology and nanostructure features of dCuO have been characterized with the HRTEM and SEM techniques. Electrochemical impedance spectroscopy characterisation (EIS) test showed that dCuO@rGO composite with a straight line which displaying the faster electron transfer rate compared to the Rct value obtained on dCuO (267 Ω) and rGO (47 Ω), this high conductivity was according with cyclic voltammetry (CV) results. It was ascribed to the octahedral hollow, porosity dCuO accelerated the electrolyte permeation capacity, and rGO with large surface area enhancing the electro-active site. Besides, the electro-reduction formed hybrid material of dCuO@rGO with well-synergetic effect significantly promoted the conductivity property. Of noteworthy, FT-IR spectroscopy indicating the retained carboxyl groups of dCuO, which could serve as functional arm-linker for capturing 5′-NH2 modified probe DNA (S1) to build the bio-sensing electrode (S1-CS/dCuO@rGO/GCE). Differential pulse voltammetry (DPV) characterization showed this manufactured biosensor with super-highly sensitivity for colitoxin DNA detection. The specific ssDNA sequences were detected in the concentration range from 0.001 to 37.5 pM with lower detection limit value of 3.89 × 10−1 fM (S/N = 3). This biosensor also showed well discrimination ability to the non-complementary and mismatched DNA sequences.

Insights into the writing process of the mask-free nanoprinting fluid force microscopy technology

Platelets are activated immediately when contacting with non-physiological surfaces. Minimization of surface-induced platelet activation is important not only for platelet storage but also for other blood-contacting devices and implants. Chemical surface modification tunes the response of cells to contacting surfaces, but it requires a long process involving many regulatory challenges to transfer into a marketable product. Biophysical modification overcomes these limitations by modifying only the surface topography of already approved materials. The available large and random structures on platelet storage bags do not cause a significant impact on platelets because of their smallest size (only 1–3 μm) compared to other cells. We have recently demonstrated the feasibility of the mask-free nanoprint fluid force microscope (FluidFM) technology for writing dot-grid and hexanol structures. Here, we demonstrated that the technique allows the fabrication of nanostructures of varying features including grid, circle, triangle, and Pacman-like structures. Characteristics of nanostructures including height, width, and cross-line were analyzed and compared using atomic force microscopy imaging. Based on the results, we identified several technical issues, such as the printing direction and shape of structures that directly altered nanofeatures during printing. Importantly, both geometry and interspace governed the degree of platelet adhesion, especially, the structures with triangular shapes and small interspaces prevent platelet adhesion better than others. We confirmed that FluidFM is a powerful technique to precisely fabricate a variety of desired nanostructures for the development of platelet/blood-contacting devices if technical issues during printing are well controlled.

Photovoltaic induced self-powered gas sensor based on 2D MoS2 incorporated NbSe2 nanorods heterostructure for NH3 gas sensing at room temperature

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted significant attention for their optical and gas-sensing applications due to their exceptional sensitivity. Reliable selectivity and low power consumption are two major requirements for photodetector and gas sensor applications in next-generation electronic devices and the Internet of Things. Self-powered sensors (especially photovoltaic gas sensors) can solve these problems. In this study, for the first time, we report 2D TMDs (NbSe2-MoS2 hybrid) on a SiO2/Si substrate to fabricate photovoltaic self-powered gas sensors. The gas sensors are operated by the photovoltaic effect of the NbSe2-MoS2 nanostructure, which is prepared using the liquid phase exfoliation process. Initially, it was revealed that the present hybrid material exhibits photovoltaic properties under light illumination, with a circuit current of 0.25 µA and a circuit voltage of 34 mV. The NbSe2-MoS2 nanostructure characteristics were then used for NH3 gas sensing at different concentrations, and the gas sensing response was detected from low (8.8 % at 10 ppm) to high (28.8 % at 500 ppm) concentrations. The built-in electric field occurred between the NbSe2-MoS2 junction and eventually operated as a driving force for NbSe2-MoS2 gas sensing without an external bias voltage. The physisorption of gas molecules on their surface prompts a charge-transfer mechanism that improves the gas sensor response. The combined outcome of NbSe2-MoS2 heterostructures could pave way to next-generation gas sensing device fabrications.

Influence of phase transition with annealing temperature on structural, morphological, and supercapacitive characteristics of molybdenum oxide nanostructures

In this study, molybdenum oxide nanostructures (MoO3 NSs) were effectively synthesized through a simple, low-cost, surfactant-free, low-temperature, and scalable chemical co-precipitation method and investigated their synergistic effect with annealing temperature on energy storage applications for the first time. Herein, we have reported a phase transition of MoO3 NSs from hexagonal to orthorhombic after the annealing temperature varied from 100°C to 500°C at constant time. Additionally, the resultant NSs were thoroughly examined for their physio-chemical characteristics, which revealed the stable phase formation of the MoO3 NSs, respectively. Furthermore, the electroactive MoO3 NSs were pasted on Ni-foam substrate (M@NF), and electrochemical properties were evaluated using a three-electrode setup at room-air temperature in 1 M KOH aqueous electrolyte across the potential range of 0 V to 0.786 V. As a result, the M@NF-5 electrode exhibited an impressive specific capacitance of 976.84 F g−1 at a scan rate of 1 mV s−1, a higher energy density of 73.69 Wh kg−1, and a power density of 655 W kg−1 at 5 mA g−1. The non-linear galvanostatic charge-discharge (GCD) profile aligns well with the cyclic voltammetry (CV) analysis. Both CV and GCD techniques confirm the pseudocapacitive behavior, with 83% capacitive retention observed after 2000 cycles. The fabricated symmetric device (M@NF-5//M@NF-5) exhibits enhanced electrochemical performance with a specific capacitance of 67.35 F g−1 at 5 mA g−1 and with an energy density of 18 Wh kg−1, and a power density of 1750 W kg−1 at a specific current. These findings underscore the potential of chemically deposited α-MoO3 as an auspicious material for use in supercapacitor applications.

Effect of Ga doping on the structural, optical, and electrical properties of ZnO nanopowders elaborated by sol-gel method

Nanostructured ZnO has received a considerable amount of interest, owing to its unique physical and chemical characteristics, as well as its remarkable performance in the fields of electronics, optics, and photonics. This work aims to study the influence of Ga dopant on the structural, optical, and electrical properties of ZnO nanopowders. Undoped and Ga-doped ZnO (GZO) nanopowders were successfully synthesised with the soft chemical sol-gel method. The solution was prepared using zinc acetate dihydrate and gallium (III) nitrate hydrate as precursors. The ethylene glycol is used as solvent. The X-ray diffractometer, scanning electronic microscope (SEM), UV–Vis, FTIR, and four-point probe method are used to analyse the properties of the synthesised powders. XRD and FTIR measurements show the growth of pure and Ga-doped ZnO crystals, which have a hexagonal wurtzite structure, and the average crystallite size varies from 9.09 nm to 24.8 nm. The nanospherical morphology of the nanopowders synthesised can be seen in the SEM images. The UV–visible spectroscopy shows that the optical gap energy increases with Ga concentration, from 3.59 eV to 3.67 eV. The I-V electrical measurements indicate that the breakdown voltage and the non-linear coefficient increase with Ga doping. This study will open the way for the investigation of a relationship between the electrical and nanostructural features of ZnO-based varistors for future device applications.

Single crystalline molybdenum nanostructure for generating reflective micro-focal spot X-rays: Structure-controllable preparation and characteristic-selectable radiation

The use of properly designed nanostructured anode targets enables direct generation of high performance X-rays. In particular, this scheme has attracted widespread research interest for obtaining micro-focal spot X-ray radiation. In this study, we developed a thermal evaporating deposition technique and achieved controllable preparation of different single crystalline molybdenum (Mo) nanostructures by exploiting the lattice matching relationship between the substrate and the product crystal orientation. When used as an anode target for a reflective X-ray radiation device, these nanostructured Mo single crystals exhibit advantages over traditional targets at larger radiation angles. Further experimental and simulation results demonstrate the geometric characteristics of these Mo nanostructures and their correlation with the radiation intensity, focal spot size, and brightness of the generated X-rays. Among them, a unique frustum of square pyramid single crystalline Mo nanostructure stands out, due to its combination of three-dimensional body feature of nanostructures and radiation plane feature of planar targets. The research results not only provide a class of nanostructured anode target materials for reflective X-ray sources with different radiation angle requirements, but also make it possible to design and develop miniaturized devices for X-ray sources with selectable radiation performance and micro-focal spot.

Enhanced photocatalytic and electrochemical performance of hydrothermally prepared NiO-doped Co nanocomposites.

In this study, we synthesize nanostructured nickel oxide (NiO) and doped cobalt (Co) by combining nickel(II) chloride hexahydrate (NiCl2.6H2O) and sodium hydroxide (NaOH) as initial substances. We analyzed the characteristics of the product nanostructures, including their structure, optical properties, and magnetic properties, using various techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet absorption spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, and vibrating sample magnetometers (VSM). The NiO nanoparticles doped with Co showed photocatalytic activity in degrading methylene blue (MB) dye in aqueous solutions. We calculated the degradation efficiencies by analyzing the UV-Vis absorption spectra at the dye's absorption wavelength of 664 nm. It was observed that the NiO-doped Co nanoparticles facilitated enhanced recombination and migration of active elements, which led to more effective degradation of organic dyes during photocatalysis. We also assessed the electrochemical properties of the materials using cyclic voltammetry (CV) and impedance spectroscopy in a 1mol% NaOH solution. The NiO-modified electrode exhibited poor voltammogram performance due to insufficient contact between nanoparticles and the electrolyte solution. In contrast, the uncapped NiO's oxidation and reduction cyclic voltammograms displayed redox peaks at 0.36 and 0.30 V, respectively.

Tailoring crystal structure of high-entropy carbides in Si-based ceramic nanocomposites through precursor engineering

High-entropy carbides with tunable crystallization and growth have been demonstrated using single-source precursor derived ceramic route. The in situ nanocrystallization of high-entropy carbide phases, (Ta0.2W0.2V0.2Mo0.2Nb0.2)SiδC and (Ta0.167W0.167V0.167Mo0.167Nb0.167Si0.167)C in amorphous Si-based ceramic matrices was achieved by using polysiloxanes and polycarbosilanes as polymer precursors respectively. The results exemplify a prominent role of the architectures of the polymeric precursors in controlling the structural features of these ceramics at various length scales. In particular, it was observed that high-entropy carbides with rock salt and zinc blende crystal structures were formed when polysiloxanes and polycarbosilanes with different backbone structure were used as polymeric precursors respectively. This is attributed to the thermodynamics of nucleation of the carbidic phases in these nanocomposites. Furthermore, the precursor architecture that dictates free carbon content, influenced nanostructural features and porosity in the material. Therefore, engineering such compositionally complex phases is feasible by selecting suitable polymeric precursors.