Porous Titanium Carbide Research Articles

CVD-Synthesized Titanium Carbide Nanoflowers as High-Performance Anodes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have emerged as promising candidates for energy storage applications due to the abundance and low cost of sodium. However, the larger radius of sodium ions limits their diffusion kinetics within electrode materials and contributes to electrode volume expansion. Here, we successfully synthesized porous titanium carbide (TiC) nanoflowers through chemical vapor deposition (CVD). The TiC nanoflowers exhibit exceptional electrochemical performance as SIB anodes, with their porous structure enhancing the conductivity, mechanical stability, and Na-ion diffusion. The TiC nanoflowers demonstrate a high reversible specific capacity of 73.5 mAh g-1 at 1 A g-1 after 2500 cycles, corresponding to an impressive capacity retention of 80.81%. Additionally, we developed a full sodium-ion cell utilizing TiC nanoflowers as the anode and Na3V2(PO4)3 as the cathode, which demonstrates a substantial reversible capacity and outstanding cycling stability. Our work presents a promising strategy for synthesizing nanostructured TiC materials as anode electrodes for SIBs.

Biomimetic Porous MXene Antibacterial Adsorbents with Enhanced Toxins Trapping Ability for Hemoperfusion.

2D transition metal carbides and nitrides, i.e., MXene, are recently attracting wide attentions and presenting competitive performances as adsorbents used in hemoperfusion. Nonetheless, the nonporous texture and easily restacking feature limit the efficient adsorption of toxin molecules inside MXene and between layers. To circumvent this concern, here a plerogyra sinuosa biomimetic porous titanium carbide MXene (P-Ti3C2) is reported. The hollow and hierarchically porous structure with large surface area benefits the maximum access of toxins as well as trapping them inside the spherical cavity. The cambered surface of P-Ti3C2 prevents layers restacking, thus affording better interlaminar adsorption. In addition to enhanced toxin removal ability, the P-Ti3C2 is found to selectively adsorb more middle and large toxin molecules than small toxin molecules. It possibly originates from the rich Ti-deficient vacancies in the P-MXene lattice that increases the affinity with middle/large toxin molecules. Also, the vacancies as active sites facilitate the production of reactive oxygen under NIR irradiation to promote the photodynamic antibacterial performance. Then, the versatility of P-MXene is validated by extension to niobium carbide (P-Nb2C). And the simulated hemoperfusion proves the practicability of the P-MXene as polymeric adhesives-free adsorbents to eliminate the broad-spectrum toxins.

Direct detection of dithiocarbamate fungicides by SALDI/MS using porous TiC ceramic powder as a substrate.

Dithiocarbamate fungicides (DTCs) have been widely used all over the world. Some of them show toxicities, such as growth toxicity and teratogenicity. Therefore, the analysis of DTCs in environments or crops is very significant. However, their direct and individual analysis was difficult, because most of them are metal complex compounds and have macromolecular properties and a low solubility in water or organic solvents. In the conventional analytical methods for DTCs, the total amount of DTCs was obtained by the quantification of the derivatives of the ligand or by measuring the carbon disulfide formed by the decomposition of the fungicides. Surface assisted laser desorption (SALDI)/MS can detect various compounds, such as metal complexes and macromolecules, present in a nanostructured substrate. The porous titanium carbide (TiC) ceramic powder shows adsorptive properties to various substances and can be used as a substrate for SALDI/MS. In this study, a method for the individual and direct detection of dithiocarbamate pesticides by SALDI/MS using porous TiC ceramics as a substrate has been developed. The dithiocarbamate fungicide was mixed with the porous TiC powder in a mortar, and the mixture was analyzed by SALDI/MS. The deprotonated ion of the ethylene-bis-dithiocarbamate complex, mancozeb or zineb, was detected in the negative ion mode. For the dimethyldithiocarbamate complexes, ferbam and ziram, the ion of the eliminated dithiocarbamate ligand was detected in the positive ion mode. Calibration curves by the present method for Manzeb showed good linearity by using an internal standard material. Based on these results, we concluded that this method is useful for the analysis of DTCs.

Ni-Activated and Ni-P-Activated Porous Titanium Carbide Ceramic Electrodes as Efficient Electrocatalysts for Overall Water Splitting.

Developing electrocatalysts based on transition-metal carbides that can be utilized for commercial water splitting is a challenging endeavor. To address this challenge, we employed a novel approach that merged phase-inversion tape-casting and sintering, subsequently implementing a simple and efficient electrodeposition process, to synthesize Ni-activated and Ni-P-activated titanium carbide (Ni/TiC, Ni-P/TiC) ceramic electrodes as water splitting catalytic cathodes and anodes. These self-supported Ni/TiC and Ni-P/TiC electrodes are binder-free with abundant finger-like pores, which contribute to the formation of highly conductive skeleton and more exposed active sites for direct water splitting. These catalysts exhibit outstanding performance, superior to many reported bifunctional nickel-based catalysts supported on other substrates. Moreover, the exceptional electrocatalytic performance of the Ni/TiC and Ni-P/TiC catalysts is attributed to the synergistic effect between Ni oxides (phosphides) and TiC, as revealed by density functional theory (DFT) calculations. This self-template strategy paves the way for fabricating industrially applicable electrodes to generate hydrogen and oxygen through water splitting.

Thermal and Structural Characterization of a Titanium Carbide/Carbon Composite for Nuclear Applications

In the framework of ISOL (isotope separation on-line) facilities, porous carbides are among the most employed target materials for the production of radioactive ion beams for research. As foreseen by the ISOL technique, a production target is impinged by an energetic particle beam, inducing nuclear reactions from such an interaction. The resulting radionuclides are subsequently released, thanks to the high target working temperature (1600-2000 °C); ionized; and extracted into a beam. Since the target microstructure and porosity play a fundamental role in the radionuclide release efficiency, custom-made target materials are often specifically produced, resulting in unknown thermal and structural properties. Considering that such targets might undergo intense thermal stresses during operation, a thermal and structural characterization is necessary to avoid target failure under irradiation. In the presented work, a custom-made porous titanium carbide that was specifically designed for application as an ISOL target was produced and characterized. The thermal characterization was focused on the evaluation of the material emissivity and thermal conductivity in the 600-1400 °C temperature range. For the estimation of a reference material tensile stress limit, the virtual thermoelastic parameter approach was adopted. In particular, for the aforementioned temperature range, an emissivity between 0.7 and 0.8 was measured, whereas a thermal conductivity between 8 and 10 W/mK was estimated.

Porous and carboxyl functionalized titanium carbide MXene sheets for fast oil-in-water emulsion separation

Titanium carbide MXene as a novel two-dimensional nanomaterial receives more attention in membrane separation, but its low water permeability has limited its application in wastewater treatment. Hence, we developed a new type of “oxidation-etching” method to fabricate porous titanium carbide MXene sheets to optimize the water channel. Meanwhile, carboxyl functionalized surface modification endowed porous MXene sheets with more hydrophilic groups, which was good for the improvement of membranes’ wettability. The as-prepared membranes exhibited superior underwater wettability, concretely, underwater contact angle up to 159.2° and sliding angle as low as 1.0°. Most importantly, the membrane displayed a high permeance (8083 L m−2 h−1 bar−1) for separating the oil-in-water surfactant-stabilized emulsion and was superior to most of the MXene membranes reported so far. It also exhibited an excellent separation performance for those emulsions prepared from high viscosity oil phases. This study reports a new “oxidation-etching” method to fabricate porous MXene sheets and carboxyl functionalized ensures the membrane with excellent underwater wettability and emulsions separation performance.

Self-propagating high-temperature synthesis of porous titanium carbide blanks for subsequent infiltration by melts

The results of self-propagating high-temperature synthesis in the open air in order to obtain porous framework made of titanium carbide for subsequent infiltration by melts are described. The optimal composition of the initial charge made of titanium and carbon powders is revealed based on the data of microstructural and X-ray phase analysis. It is shown that the sample of the recommended composition has sufficient indicators of total and open porosity and is characterized by high values of specific load during compression tests.

Adherent diamond coating deposited on Ti by ultrasonic after carbonization pretreatment

The adhesion of wear-resistant diamond coating deposited on titanium was weakened by the porous titanium carbide interlayer, which was formed before film growth. In order to enhance substrate-coating adherence, a new pretreatment method was presented: Ti substrates were carbonized by hot filament chemical vapor deposition system, and then the carbonized substrates were ultrasonically vibrated using diamond micro-powder suspension. Diamond coatings were deposited by hot filament chemical vapor deposition as well. The effect of carbonization time on adhesion was investigated. The carbonized substrates and the interface between diamond coatings and substrates were characterized. The results showed that as the carbonization time increases, porous structures and cracks appear and increase on the surface of the substrate. The carbonized substrates possess high surface energy and thus the nucleation is promoted. After deposition, a dense and thin titanium carbide was observed. Ultrasonic after carbonization pretreatment can significantly enhance the adhesion of Ti-based diamond coatings by promoting nucleation and suppressing the formation of porous titanium carbide.

Achieving Ultrahigh Energy Densities of Supercapacitors with Porous Titanium Carbide/Boron‐Doped Diamond Composite Electrodes

AbstractThe energy densities of most supercapacitors (SCs) are low, hindering their practical applications. To construct SCs with ultrahigh energy densities, a porous titanium carbide (TiC)/boron‐doped diamond (BDD) composite electrode is synthesized on a titanium plate that is pretreated using a plasma electrolytic oxidation (PEO) technique. The porous and nanometer‐thick TiO2 layer formed during PEO process prevents the formation of brittle titanium hydride and enhances the BDD growth during chemical vapor deposition processes. Meanwhile, the in situ conversion of TiO2 into TiC is achieved. Combination of this capacitor electrode with soluble redox electrolytes leads to the fabrication of high‐performance SCs in both aqueous and organic solutions. In 0.05 m Fe(CN)63−/4− + 1 m Na2SO4 aqueous solution, the capacitance is as high as 46.3 mF cm−2 at a current density of 1 mA cm−2; this capacitance remains 92% of its initial value even after 10 000 charge/discharge cycles; the energy density is up to 47.4 Wh kg−1 at a power density of 2236 W kg−1. The performance of constructed SCs is superior to most available SCs and some electrochemical energy storage devices like batteries. Such a porous capacitor electrode is thus promising for the construction of high‐performance SCs for practical applications.

Effects of TiC addition on microstructures, mechanical properties and fracture behaviors of porous titanium carbide ceramics

The porous TiC ceramics were prepared by the powder metallurgy-reaction sintering method, in which TiO2, carbon black, phenolic resin and original TiC powder were used as the raw materials. The results indicate that the addition of original TiC powder can affect the microstructures, densities, porosities, mechanical properties and fracture behaviors. With the increase of the TiC addition content, the grain size of secondary TiC, the bulk density and the pore size increase, meanwhile the pore size distribution broadens and the porosity decreases gradually. However, the bending strength does not display a trend of monotone variation, and the maximum bending strength reaches 54.97 MPa when the amount of TiC addition is 30%. In addition, the fracture morphologies of the bending specimens show that the fracture of the secondary TiC grain is usually an inter-granular fracture along the grain boundary. When cracks encounter the original TiC particles, three fracture ways may present, i.e. crack deflection, inter-granular fracture and trans-granular cleavage fracture of the original TiC grains.

Fabrication of porous titanium carbide ceramics by gelcasting process

Titanium carbide ceramics with high porosity were fabricated by gelcasting process with methacrylamide as a chain forming monomer, methylenebisacrylamide as a cross-linker monomer and tetramethylammonium hydroxide as a dispersant. The stability of suspension, mechanical properties, phase composition and microstructure were investigated by zeta potential, bending and compressive strengths, X-ray diffraction and scanning electron microscopy (TEM) analyses, respectively. The results show that the optimal concentration of dispersant for the best homogeneous unagglomerated microstructures is 0.4 wt% at pH 9. The highest green strength of 33 MPa is obtained from the suspension with 40 vol% solid loading and 25 wt% monomer. The porosity increases with the increase in monomer content and the decrease in solid loading. Also, the strength of porous TiC ceramic decreases with the content of pores increasing in the sintered ceramics.

Effects of infiltration parameters on the synthesis of nano-laminated Ti3SiC2

ABSTRACTIn this paper, the nano-laminated Ti3SiC2 ceramics were fabricated by liquid silicon infiltration of gelcast porous titanium carbide (TiC) preforms. The phase compositions and microstructures of the synthesized samples at various infiltration times and temperatures were analyzed by the X-ray diffraction (XRD) technique and were observed by field emission scanning electron microscopy (FESEM). The results showed that the formed Ti3SiC2 decomposes to the TiC phase with the increase of infiltration time. It was found from the XRD patterns that the samples with an 88 wt% Ti3SiC2 MAX phase can be produced with infiltration at 1500°C for 1 h with 50 vol% solid loading and 10 wt% monomer content. It is found that the hardness and flexural strength of Ti3SiC2-based ceramic has been reduced with a decrease in SiC and TiC impurities and reach 5.8 GPa and 420 MPa, respectively, for the sample with 15 wt% impurity. The microstructure evaluation revealed that the purity and properties of samples were affected both through the gelcasting and infiltration parameters.

Study on Microstructures and Properties of Porous TiC Ceramics Fabricated by Powder Metallurgy

Powder metallurgy process was used to fabricate porous titanium carbide (TiC) ceramics, in which TiC powders were taken as the raw materials, nickel was used as the metallic binder and urea was the space-holder. Microstructure, composition and phase of porous TiC ceramics were characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Flexure strength of the porous TiC ceramics was tested by a three-point bending method. The results show that macropores and micropores coexist in the prepared porous TiC ceramics. Moreover, the pore number, size and distribution in porous TiC ceramics can be controlled on demand. Particularly, the factors such as the number or size of space-holder, compacting pressure and Ni content have significant effect on the porosity and flexure strength.

Facile synthesis of nanoporous TiC–SiC–C composites as a novel counter-electrode for dye sensitized solar cells

Highly mesoporous titanium carbide (TiC) based composites were synthesized through a simple carbothermal reduction of homogenous monoliths which were prepared by a one-pot sol–gel process. Their application properties as a counter electrode of dye-sensitized solar cells (DSSC) were evaluated in this paper. The surface area (116–368m2/g), average particles size (14–87nm) and pore size (4–9.2nm) of the mesoporous composites can be easily tuned by altering chemical compositions of the precursor. Introduction of silicon into the Ti–C–O system significantly reduced the average carbide grain size and also enhanced the mesoporousity of TiC composites. The dye-sensitized solar cell using a PEDOT:PSS doped TiC–SiC–C composite as the counter electrode showed a notable efficiency of 5.7%, which doubled that of pure PEDOT:PSS cell. Potentially, the reported method could be a convenient route to fabricate porous TiC based composites for other functional applications.

Application of the powder of porous titanium carbide ceramics to a reusable adsorbent for environmental pollutants

The aim of this study is to investigate the utilization of the powder of porous titanium carbide (TiC) ceramics as a novel adsorbent or a material for solid-phase extraction (SPE). The adsorption and elution of inorganic and organic pollutants, Pb(II), 2,4,6-trichlorophenol (TCP), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), to the material were evaluated. The cartridge packed with TiC ceramics powder was used for the extraction test of pollutants. The solution containing pollutants at 1.0 μg mL −1 was passed through the TiC cartridge, and the substances were almost quantitatively removed. Furthermore, the pollutants retained in the cartridge were eluted with 3 N HCl for Pb(II) and with methanol for organic pollutants. The recoveries of pollutants were over 80%. In addition, we used the TiC cartridge for the solid-phase extraction of water samples (500 mL each of the distilled water and the river water) by adding pollutants at determined concentrations. Every pollutant was adsorbed almost quantitatively, and eluted by 3 N HCl or methanol. From these results, we concluded that the powder of porous TiC ceramics is a useful reusable adsorbent for the water cleanup and solid-phase extraction.

Combustion Synthesis of Porous TiC/Ti Composite by a Self-Propagating Mode.

Porous titanium carbide (TiC) and TiC/Ti composites were synthesized by self-propagating high-temperature synthesis (SHS). Titanium and carbon powders were blended by various Ti/C blending ratios. The heat of reaction between titanium and carbon was high enough to induce the self-sustaining reaction of TiC formation on condition that some processing parameters (Ti/C ratio and porosity of the precursor) were appropriately selected. When the Ti/C blending ratio was high, the excess amount of titanium absorbed the heat of reaction. Consequently, the heated zone was not heated up to the ignition temperature. On the other hand, when the Ti/C ratio was low, high thermal conductivity of the precursor prevented an ignition of the heated side of precursors. The pore morphology was controlled by changing the Ti/C ratio and the preheat temperature.

Low Temperature Synthesis and Characterization of Nanocrystalline Titanium Carbide with Tunable Porous Architectures

High surface area, porous titanium carbide films have been synthesized at room temperature via reactive ballistic deposition (RBD). X-ray diffraction and X-ray photoelectron spectroscopy show that evaporative deposition of titanium in an ethylene ambient environment allows for low temperature (35 °C) synthesis of nanocrystalline titanium carbide, a material which typically requires high processing temperatures to produce. Angle-dependent RBD allows for the controlled tuning of TiC nanostructure and porosity where changing the deposition angle from near normal incidence (13°) to more glancing angles (50−85°) changes the film morphology from relatively nonporous, dense TiC to a continuous, reticulated TiC and finally to discrete, nanocolumnar TiC. The influence of the deposition angle on TiC optical constants, porosity, specific surface area, and the pore size distribution has been investigated using hybrid quartz crystal microbalance and ellipsometric porosimetry. Notably, TiC films deposited at 35 °C at an angle of 70° have a specific surface area of 710 m2·g−1 and a mean Kelvin radius of 1.8 nm, making them attractive materials for application in catalysis, energy conversion, and storage.

Growth and Characterization of High Surface Area Titanium Carbide

High surface area, porous titanium carbide (TiC) films have been synthesized employing physical vapor deposition of titanium at glancing angles under high vacuum within an ethylene ambient. The composition, surface area, and morphology of the TiC films were studied as a function of deposition conditions including ethylene pressure, titanium deposition angle, substrate temperature during growth, and postdeposition annealing temperature. At high or glancing deposition angles (∼80−85°) synthesis produces films composed of arrays of porous nanocolumns of TiC, while deposition at more moderate angles, less than 70°, results in continuous, reticulated films. The maximum specific surface area (840 m2/g) is obtained by growth with an incident titanium deposition angle of 65°, an ethylene pressure of 1.5 × 10−7 Torr, and a substrate growth temperature of ∼350 K. This result is in contrast to previous investigations using related physical vapor deposition techniques which have generally shown that films with the gr...

Porous titanium carbide ceramics fabricated by coat-mix process

Porous titanium carbide ceramics are fabricated by the coat-mix process with phenolic resin as the carbon source, and titania powders as the titanium source. The phase composition, residual free carbon content, and microstructure have been investigated by X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy, respectively. The results indicate that phase-pure titanium carbide materials can be obtained using this process. A large number of pores exist in the fabricated titanium carbide ceramics.

Paper derived biomorphic porous titanium carbide and titanium oxide ceramics produced by chemical vapor infiltration and reaction (CVI-R)

Chemical vapor infiltration (CVI) is used for producing biomorphic porous TiC ceramics derived from paper. The paper samples are first carbonized in inert atmosphere to yield biocarbon template structures (C b-template). Subsequently, three routes for converting the C b-templates into TiC ceramics are studied. The first route includes CVI with TiCl 4-H 2. The effect of methane as additional carbon source is investigated on the second route (TiCl 4-H 2-CH 4). Finally, a two step CVI process (Route 3), first TiCl 4-H 2 and subsequent TiCl 4-H 2-CH 4, is performed in order to improve both the grade of conversion of the C b-template into TiC and the mechanical properties of the resulting porous TiC ceramics. Furthermore, porous TiO 2 ceramics are produced by high temperature oxidation of the TiC ceramics in air flow.