Nanostructured Carbide Research Articles

Creation of a nickel composite using surface structuring of the reinforcing phase with titanium carbide nanostructures to improve strength properties

Abstract The development of metal matrix composite (MMC) materials is one of the demanded areas of research in materials science. In line with this trend, there is an increasing interest in nickel-based MMC materials, which have already become classic in science and technology. This is due to the high demand for Ni-based materials with high strength characteristics, high hardness, and increased heat resistance. In this research, we proposed an approach to obtain a MMC material using the surface structuring process, ALD (Atomic Layer Deposition) and powder metallurgy method. The developed approach provides a composite with TiC nanostructures (1-5 nm) uniformly distributed throughout the Ni matrix. The absence of interphase boundaries between the Ni matrix particles and carbide nanostructures made it possible to minimize the internal porosity of the sample. This is due to the strength of the interphase boundaries between the matrix and the reinforcing phase in the composite and to the solidity of the structure. As a result, the created material effectively resists plastic deformation and stress. This allows not only to enhance the strength properties of the composite, but also to maintain the MMC plasticity, which increases its processing ability.

Hydrogen-designed spin-states of 2D silicon carbide and graphene nanostructures.

Identifying and manipulating spin in two-dimensional materials is of great interest in advancing quantum information and sensing technologies, as well as in the development of spintronic devices. Here, we investigate the influence of hydrogen adsorption on the electronic and magnetic properties of graphene-like triangulenes. We have constructed triangulenes from SiC monolayers, which have been successfully synthesized very recently, extending our investigation to include graphene triangulenes. This advancement in the synthesis of SiC monolayers allows us to investigate deeper into the unique properties of SiC-based triangulenes and compare them with their graphene counterparts. The addition of hydrogen has been found to induce a magnetic moment in the SiC monolayer, with a more localized spin density when H is adsorbed in the C sites while spreading through the lattice when adsorbed on the Si sites. In triangular flakes, the ground spin state changes with the adsorption site: decreasing multiplicity on edge-defined sublattices and increasing it on the opposite sublattice. These findings suggest hydrogen adsorption as a tool for tuning spin-state properties in SiC and graphene nanostructures, with potential applications in spintronics and spin quantum dot devices.

Retraction Note: Artificial photoactive chlorophyll conjugated vanadium carbide nanostructure for synergistic photothermal/photodynamic therapy of cancer

Retraction Note: Artificial photoactive chlorophyll conjugated vanadium carbide nanostructure for synergistic photothermal/photodynamic therapy of cancer

Features of processes of high-speed milling with a complex profile tool in the processing of aluminum alloys and composite materials

Complex computational and experimental studies substantiate rational modes of milling of complex contour equiaxed surfaces with high accuracy of shape, dimensions and roughness parameters. Bars made of nanostructured carbide composite (produced by extrusion of WC-Co-Al2O3 bimodal powder mixtures) with increased strength, crack resistance and heat resistance were used as a workpiece material for the manufacture of new original tool designs. The combination of these properties is a necessary prerequisite for the effective operation of the developed designs of multi-blade cutters at high cutting speeds and under conditions of variable cyclic loads. A more complex kinematics of the joint rotational movement of the tool during milling dictates the need for new approaches when assigning rational cutting modes. To obtain reliable calculation formulas, numerical experiments were previously carried out, including simulation of the processing process using the VisualStudio integrated development environment, which supports WindowsForms technology. The ability to display graphical 3D objects was implemented using an additional software product in the form of the Open CASCADE geometric core. Numerical experiments using MathCAD software products and based on the analytical provisions proposed in the work made it possible to evaluate the influence of cutting conditions, geometric parameters of the cutting part of the tool (profile and number of teeth), kinematics of relative movement in the “tool – part” system on the shape of surfaces and contour parameters (roughness obtained during milling. A technique, algorithm and program for the automated calculation of cutting conditions has been developed, which has been verified during full-scale experiments and the manufacture of complex profile parts from aluminum alloys for drives of aerospace products (in the form of a RC profile and parts of a pinion transmission of guidance mechanisms). At the same time, on the basis of a 3D model of products, control programs for CNC machines were created using MasterCAM. The practical significance and technical and economic efficiency of the proposed design and technological solutions is to increase productivity and reduce the complexity of processing (in comparison with the basic options) through the use of new multi-edge carbide tools for high-speed milling (including when processing composite materials).

Chemical Functionalization of Silicon Carbide Nanotube (SiCNT): First Principles DFT Study

In this study, a functionalized nano drug carrier design based on (5,5) silicon carbide nanotube and functional groups such as amine (−NH2), hydroxyl (−OH), and carboxylic acid (−COOH) were investigated using the first principles’ density functional theory. The critical need for a smart nanocarrier system aims to increase the concentration of medications to the particular tissues of interest with minimal toxicity to the patient. The simulations are carried out using Quantum ATK-Atomistic Simulation Software. The negative binding energy and the total energy difference obtained by optimization through random perturbation ensure the stability of the structures SiCNT and SiCNT-(X/2X) (X = −OH, −NH2, and −COOH). The energy bandgap obtained for the pristine structure is 1.99 eV indicating their indirect bandgap semiconducting characteristics. In comparison to SiCNT, the energy bandgap of SiCNT-(X/2X) structures decreases within a range of 0.06 eV to 1.95 eV, respectively. Partial charges and p-character were used to understand the nature of bonds between the nanotube and the functional moiety. The chemical potential analysis favors a blue shift of SiCNT-(X/2X) with respect to SiCNT. The higher values of ionic character and solvation energy predicts the solubility of nanostructures in the aqueous medium. In comparison to all analyzed systems, the findings of the ionic character, solvation, and sensing mechanism indicate SiCNT-(2NH2) system to be most favorable drug delivery nanocarrier. These findings suggest that increasing the concentration of −NH2 functional groups on the side wall of silicon carbide nanotubes helps to develop a promising and efficient targeted drug delivery system to deliver specific molecular cargo to the cells mitigating toxicity associated with nanotubes, thereby enhancing the outcomes of cancer treatment. Furthermore, surface functionalization of silicon carbide nanostructures could improve their potential solubility parameterized by higher values of dipole moment and solvation energy together with enhanced biocompatibility leading to the desired therapeutic effect.

Efficient flexible electrodes for lithium-ion batteries utilizing well-dispersed hybrid Mo2C nanoparticles on vertically-oriented graphene nanowalls

Flexible lithium-ion batteries (LIBs) have gained significant interest as potential power source solutions for wearable and flexible electronic devices. However, the fabrication of flexible LIBs with optimal flexibility, mechanical stability, and high energy density remains a formidable challenge for researchers. Transition metal carbides are being investigated as capable anode materials for advanced lithium-ion batteries. In this study, we explore the growth of molybdenum carbides (Mo2C) and vertically-oriented graphene nanowalls (VGNWs) on flexible graphite paper (Papyex®) and their potential application as anode material for Lithium-Ion batteries (LIBs). Our approach involves a bottom-up synthesis of binder-free hybrid electrodes through the deposition of Mo carbide nanostructures on VGNWs using a combination of chemical vapour deposition, magnetron sputtering, and thermal annealing processes. The hybrid structure of Mo2C/VGNWs exhibits distinct and specialized attributes, including remarkable structural durability, small particle size, and a porous configuration. These features effectively promote the accessibility of electrons and ions to the interface between the electrode and electrolyte. Our electrochemical tests demonstrate that the Mo2C/VGNWs hybrids show superior lithium storage behavior when compared to VGNWs/Papyex® electrodes. The synergistic effects of the Mo2C nanoparticles and the highly conductive VGNW are mainly responsible for the enhanced electrochemical characteristics.

Manufacturing of Novel Nanostructured TiCrC Carbides Using Mechanical Alloying and Spark Plasma Sintering

Dense nanostructured carbides existing in ternary system Ti-Cr-C were elaborated thanks to a two-steps method. In the first step, nanostructured Ti0.9Cr0.1C carbides were prepared by high-energy planetary ball milling under various times (5, 10, and 20 h), starting from an elemental powder mixture of titanium, chromium, and graphite. In the second step, these nanostructured powders were used to produce densified carbides thanks to the spark plasma sintering (SPS) process under a pressure of 80 MPa. The temperature was fixed at 1800 °C and the holding time was fixed at 5 min. Microstructural characteristics of the samples were investigated using X-ray diffraction (XRD). Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) was used to investigate the morphology and elemental composition of the samples obtained using SPS. The novelty of this work is to understand the effect of SPS on the microstructural and electrochemical properties of the nanostructured Ti0.9Cr0.1C carbides. The XRD results showed that, during sintering process, the (Ti,Cr)C carbide was decomposed into TiC, Cr7C3, and Cr3C2 phases. An amount of iron was detected as contamination during milling, especially in the case of a sample obtained from 20 h milled carbide. The bulk obtained from the milled powders for 5 and 20 h present similar relative densities of 98.43 and 98.51%, respectively. However, the 5 h milled sample shows slightly higher hardness (93.3 HRA compared to 91.5 HRA) because of the more homogeneous distribution of the (Ti,Cr)C phases and the low iron amount. According to the 0.0011 mm/year corrosion rate and 371.68 kΩ.cm2 charge transfer resistance obtained from the potentiodynamic polarization and EIS tests, the 20 h carbide was the specimen with the highest corrosion resistance.

Hybrid Nanostructured Compounds of Mo2C on Vertical Graphene Nanoflakes for a Highly Efficient Hydrogen Evolution Reaction.

Organizing a post-fossil fuel economy requires the development of sustainable energy carriers. Hydrogen is expected to play a significant role as an alternative fuel as it is among the most efficient energy carriers. Therefore, nowadays, the demand for hydrogen production is increasing. Green hydrogen produced by water splitting produces zero carbon emissions but requires the use of expensive catalysts. Therefore, the demand for efficient and economical catalysts is constantly growing. Transition-metal carbides, and especially Mo2C, have attracted great attention from the scientific community since they are abundantly available and hold great promises for efficient performance toward the hydrogen evolution reaction (HER). This study presents a bottom-up approach for depositing Mo carbide nanostructures on vertical graphene nanowall templates via chemical vapor deposition, magnetron sputtering, and thermal annealing processes. Electrochemical results highlight the importance of adequate loading of graphene templates with the optimum amount of Mo carbides, controlled by both deposition and annealing time, to enrich the available active sites. The resulting compounds exhibit exceptional activities toward the HER in acidic media, requiring overpotentials of 82 mV at -10 mA/cm2 and demonstrating a Tafel slope of 56 mV/dec. The high double-layer capacitance and low charge transfer resistance of these Mo2C on GNW hybrid compounds are the main causes of the enhanced HER activity. This study is expected to pave the way for the design of hybrid nanostructures based on nanocatalyst deposition on three-dimensional graphene templates.

Surface morphology effects on the mechanical and electronic properties of halogenated porous 3C-SiC: A DFT study

Silicon carbide nanostructures have been widely studied due to their potential technological applications. However, the theoretical characterization, especially the effect of the surface on the mechanical properties of this material is still underexplored. In this work, we report the electronic and mechanical properties of 3C-SiC nanopores with different pore surfaces and different passivation schemes using a density functional theory approach and the supercell technique. The nanopores were modeled by removing columns of atoms in the [001] direction, thus creating four types of pores, two with an Only C or Si pore and two with a C or Si-Rich pore surface. All surfaces were passivated with hydrogen, then some atoms of H were replaced with fluorine and chlorine. Results show that pores with a higher concentration of C on the surface have a larger bandgap compared with the Si cases. Moreover, only a few changes can be observed due to passivation. For the mechanical properties the Bulk and Young’s modulus were calculated and show that the Only C structures were the most brittle and, for almost all the pores, the H + Cl passivation improve the Bulk modulus.

Synthesis and Photothermal Properties of UV-Plasmonic Group IV Transition Metal Carbide Nanoparticles

Refractory nanostructures can be low-cost and chemically and thermally robust alternatives to metal-based plasmonic materials. While transition metal nitrides have received much attention recently, there has been less emphasis on their closely related non-layered carbide counterparts. In this work, plasmonic group IV transition metal carbide (TiC, ZrC, and HfC) nanostructures were prepared using a facile magnesiothermic reduction method, which yielded a phase pure product. TiC, ZrC, and HfC with rock salt crystal structures and an average particle size of 24, 31, and 42 nm, respectively, were obtained by reacting corresponding metal oxide, magnesium, and biochar in the solid state. Calculations performed using a finite element method predicted these group IV carbide nanostructures to have localized surface plasmon resonance in the UV region between 150 and 175 nm. The photothermal transduction efficiency of each carbide was explored to further verify the plasmonic behavior. HfC was found to have the highest photothermal transduction efficiency of 73%, followed by ZrC (69%), and then TiC (60%) at 365 nm.

Electrochemical detection of enrofloxacin in meat using bimetallic organic framework-derived NiCo2O4@NiO.

A novel electrochemical aptasensor based on a bimetallic organic frame-derived carbide nanostructure of Co and Ni (NiCo2O4@NiO) was prepared for rapid and sensitive enrofloxacin (ENR) detection of sheep and pork liver meats. The composite was fabricated by solvothermal and direct pyrolysis methods and dropped onto a modified electrode to improve the electron transfer efficiency. Furthermore, different techniques such as scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the morphology and structure of the materials. Electrochemical impedance spectroscopy and cyclic voltammetry were used to evaluate the performance of the electrochemical sensor. As a result, the electrochemical aptasensor based on NiCo2O4@NiO exhibited excellent sensing performances for ENR with an extremely low detection limit of 1.67 × 10-2 pg mL-1 and a broad linear range of 5 × 10-2 to 5 × 104 pg mL-1, as well as great selectivity, excellent reproducibility, high stability and applicability. In addition, the relative standard deviation for real samples was in the range of 93.83 to 100.09% and 94.95 to 100.01% for sheep and pork liver. The results showed that the composite can be expected to greatly facilitate ENR detection and practical applications in harmful food due to the advantages of simple fabrication, controllable, large-area uniformity, environmental friendliness, and trace detection.

Silicon Carbide Nanostructures as Potential Carbide Material for Electrochemical Supercapacitors: A Review.

Silicon carbide (SiC) is a very promising carbide material with various applications such as electrochemical supercapacitors, photocatalysis, microwave absorption, field-effect transistors, and sensors. Due to its enticing advantages of high thermal stability, outstanding chemical stability, high thermal conductivity, and excellent mechanical behavior, it is used as a potential candidate in various fields such as supercapacitors, water-splitting, photocatalysis, biomedical, sensors, and so on. This review mainly describes the various synthesis techniques of nanostructured SiC (0D, 1D, 2D, and 3D) and its properties. Thereafter, the ongoing research trends in electrochemical supercapacitor electrodes are fully excavated. Finally, the outlook of future research directions, key obstacles, and possible solutions are emphasized.

Intrinsic thermal conductivities of BC3-C3N superlattice nanoribbons: A molecular dynamics study

Superlattice nanostructures enable controllable thermal conductivity minimization in nanodevices for thermoelectric applications. This is especially true regarding recently developed carbon nitride (C 3 N) and boron carbide (BC 3 ) nanostructures. In this study, we explored phonon heat transport in a superlattice nanoribbon with C 3 N and BC 3 domains using non-equilibrium molecular dynamics (NEMD) simulation. Specifically, we investigated the impacts of changing the unit cell length, nanoribbon length, average temperature, and temperature difference between the hot source and cold sink on the thermal conductivity of the nanoribbon. Based on our results, the value of the intrinsic thermal conductivity ( k ∞ ) reaches a minimum of 206 W m -1 K -1 at room temperature for a superlattice nanoribbon unit cell length of 8 . 5 nm. At infinite total length, the minimum thermal conductivity obtained for the BC 3 -C 3 N superlattice nanoribbon is about 40% and 25% of the thermal conductivities of pristine BC 3 and C 3 N nanoribbons, respectively. The observed minimum thermal conductivity in the nanoribbons is attributed to the phonons transitioning from coherent to incoherent transport, where the unit cell length is comparable to the phonon coherence length. The results of this work provide atomistic insights into the development of low-thermal-conductivity nanomaterials for thermal insulation applications.

Metal Carbide‐Based Cocatalysts for Photocatalytic Solar‐to‐Fuel Conversion

Semiconductor‐based photocatalytic solar‐to‐fuel conversion has proven an appealing strategy for achieving carbon‐neutral and green‐hydrogen production. However, almost all semiconductors exhibit unsatisfactory photocatalytic performance due to insufficient surface‐active sites, weak selectivity, and fast charge‐carrier recombination. For these reasons, cocatalyst loading has become an encouraging strategy for improving photocatalytic activity and selectivity. Owing to the scarcity, and cost of noble metal‐based cocatalysts, utilization of low‐cost noble‐metal‐free cocatalysts, such as metal carbide‐based cocatalysts, has aroused tremendous attention. This review highlights some recent crucial advances in active metal carbide‐based cocatalysts for photocatalytic solar‐to‐fuel conversion. First, the fundamentals of metal carbide‐based cocatalysts are presented, including the photocatalytic mechanism, advantages, drawbacks, and design rules. Second, three synthesis approaches of high‐active metal carbide‐based cocatalysts, namely constructing metal carbide nanostructures, epitaxial synthesis of metal carbides on nanostructured carbon, and crystal imperfection construction on metal carbides, are thoroughly addressed. Subsequently, applications of metal carbide‐based cocatalysts in photocatalytic hydrogen production, CO2 reduction, and nitrogen reduction are further discussed. Finally, the crucial challenges and important directions of metal carbide‐based cocatalysts for photocatalytic solar‐to‐fuel conversion are proposed. This review demonstrates some new options for rationally designing and developing novel and efficient metal carbide‐based cocatalysts for highly active and selective photocatalytic solar‐to‐fuel conversion.

Electrochemical Preparation of Nanocatalysts and Their Application in Electrocatalysis.

In order to solve the basic problem of high-temperature sintering of molybdenum carbide restricting the efficient construction of molybdenum carbide nanostructures and the full play of hydrogen evolution performance, this article studies the preparation of nano molybdenum carbide/boron nitrogen codoped two-dimensional carbon composite structure catalysts and the electrochemical hydrogen evolution reaction performance. Based on the self-assembly process of gelatin molecules on the surface of a two-dimensional layered boric acid crystal template, a new strategy for constructing a high-performance electrochemical hydrogen evolution reaction catalyst based on molybdenum carbide/boron nitrogen codoped two-dimensional nanocarbon composite structure (η-MoC@ BN-CSs) was established. The experimental results show that the overpotential of hydrogen evolution reaction based on molybdenum carbide/boron nitrogen codoped two-dimensional nanocarbon composite structure catalyst is 159 mV, which is slightly higher than 67 mV of commercial Pt/C catalyst, but lower than the reported literature value in the list. The Tafel slope is 68 mV·dec−1, which is slightly higher than that of the commercial Pt/C catalyst (40 mV·dec−1) and the reference value (58 mV·dec−1), but lower than those of other reported literature values in the list, indicating that the molybdenum carbide/boron nitrogen codoped two-dimensional carbon nanocomposites have excellent catalytic performance under alkaline conditions. Conclusion. This kind of two-dimensional nanocomposite structure shows platinum-like catalytic activity when used as an electrochemical hydrogen evolution catalyst in alkaline electrolyte. It has better reaction kinetics and better stability.

N, P-codoped molybdenum carbide nanoparticles loaded into N, P-codoped graphene for the enhanced electrocatalytic hydrogen evolution

Based on the ever-growing interest of heteroatoms (e.g., P, N, S, transition metals) doping into molybdenum carbide and graphene for electrochemical reactions, herein, a ternary phosphomolybdic acid-polyethyleneimine/graphene oxide nanocomposite as a suitable precursor was developed to not only uniformly hybridize molybdenum and carbon source to perform the controllable in situ growth of well-defined molybdenum carbide nanostructure on graphene by annealing, but also synchronously dope N and P atoms into molybdenum carbide crystal lattice and graphene. The as-prepared hybrid showed remarkable electrocatalytic activity and high stability for hydrogen evolution reaction in basic media, due to the following favorable features, i.e. a large accessible active sites afforded by the ultrafine molybdenum carbide, the heteroatoms doped, the regulated electronic structure, the balanced thermodynamics between hydrogen adsorption and desorption, the accelerated charge/mass transfer ability by the ultrathin and defective carbon layer, and the protection of molybdenum carbide by carbon layer. As a result, it only needed a small overpotential of 47 mV to drive 10 mA cm−2 and a low onset potential of 10 mV, as well as a small Tafel slope of 56.8 mV·dec−1, thus suggesting its promising potential for hydrogen evolution electrocatalyst.

Magnetically-supported electrically-induced formation of silicon carbide nanostructures on silicon substrate for optoelectronics applications

Magnetically-supported electrically-induced formation of silicon carbide nanostructures on silicon substrate for optoelectronics applications

Mechanical properties of metal–matrix composites reinforced with carbide structures

Metal–matrix composites based on an aluminum matrix reinforced with ceramic particles are widely used as structural materials in the aerospace and automotive industries. The main problems in the manufacture are the uniformity of the distribution of particles over the volume, poor adhesion of ceramic particles to the matrix metal, and the formation of aluminum carbide at the interfaces, leading to undesirable embrittlement. We propose a new technique for the manufacture of metal–matrix composites, which consists in creating a composite material, when carbide nanostructures form a framework in the volume of an aluminum matrix, and which allows solving the above problems. A finite element model of deformation of a metal–matrix composite reinforced with carbide structures is constructed.

RETRACTED ARTICLE: Artificial photoactive chlorophyll conjugated vanadium carbide nanostructure for synergistic photothermal/photodynamic therapy of cancer

Optically active nanostructures consisting of organic compounds and metallic support have shown great promise in phototherapy due to their increased light absorption capacity and high energy conversion. Herein, we conjugated chlorophyll (Chl) to vanadium carbide (V2C) nanosheets for combined photodynamic/photothermal therapy (PDT/PTT), which reserves the advantages of each modality while minimizing the side effects to achieve an improved therapeutic effect. In this system, the Chl from Leptolyngbya JSC-1 extracts acted as an efficient light-harvest antenna in a wide NIR range and photosensitizers (PSs) for oxygen self-generation hypoxia-relief PDT. The available large surface of two-dimensional (2D) V2C showed high Chl loading efficiency, and the interaction between organic Chl and metallic V2C led to energy conversion efficiency high to 78%. Thus, the Chl/ V2C nanostructure showed advanced performance in vitro cell line killing and completely ablated tumors in vivo with 100% survival rate under a single NIR irradiation. Our results suggest that the artificial optical Chl/V2C nanostructure will benefit photocatalytic tumor eradication clinic application.Graphical

A Review of Metal Injection Moulding on WC-Co Cemented Carbide Comprised of Grain Growth Inhibitors (GGI)

This paper aims to provide a summary of metal injection moulding technologies utilising cemented WC-Co carbides comprised of grain growth inhibitors (GGI). The advanced manufacturing of metal injection moulding (MIM) has the ability to produce cement nanostructured carbides. In addition, the nature of the feedstock plays a crucial role when manufacturing a defect-free component at each point of the MIM phase, thus the interactions between the metal powder and the binder combining, moulding, and debinding are important to be recognised. The primary objective of this analysis is to investigate the characterization of feedstock to form a homogenous mixture. There are five criteria to classify features of the feedstock which include powder characteristics, binder composition, powder content ratio, mixing cycle, and approaches to palletization. Not only that, the feedstock must meet specific criteria; higher powder loading with excellent flowability by the rheological approaches. The second goal of the research is to re-evaluate feedstock’s flow properties in relation to rheological activity in terms of index flow behaviour (n), activation energy (E), and mouldability (α). MIM practitioners have continued to underestimate erratic product quality, including inadequate regulation, distortion, and internal and external defects. These defects can arise in the early processing phases, but often occur only after sintering or debinding. The approaches are also challenging to provide. This chapter includes a description of MIM defects. Explanations are listed and recommendations are provided for these defects.