Carbon-Deficient Titanium Carbide With Highly Enhanced Hardness

Abstract

We report the synthesis of a polycrystalline specimen of TiC 1−x under high-pressure and high-temperature (HPHT) conditions. The carbon vacancy, crystal structure, Vicker hardness, elastic constants, and bond features of the synthesized specimen were investigated. Though the specimens were synthesized with stoichiometric ratio at high pressure, a robust carbon vacancy was observed using energy dispersive and X-ray photoelectron spectrum. TiC 1−x exhibits almost the highest asymptotic Vickers hardness in transition-metal light-element (TMLE) compounds. In this study, using Vickers hardness characterization, the asymptotic hardness was found to be 27.1 GPa. This exceeds the hardness of most transition metal borides with high boron concentrations. Based on the first-principles calculation of the Mulliken population of Ti-C bonds, the intrinsic high Vickers hardness of TiC 1−x is attributed to the combination of covalent Ti-C bonds and the optimized eight-valence-electron structure, while the extrinsic contribution comes from the harden effect of carbon defects. This work demonstrates that a higher concentration of light elements or a higher-dimensional light element framework is not the critical factor for higher hardness, and carbon vacancy is another way to strengthen the crystal structure.

Functionalized Ketjenblack Infusion into Expanded Interlayer Spacing of Ti3C2Tx MXene Nanosheets toward High Specific Capacitance Supercapacitors

“…Now, the chemical states of Ti, O, and C elements were examined by their respective high-resolution emission spectrum after fitting through the Gaussian method, as seen in Figure b–d. Here, the XPS spectra of Ti 2p show the appearance of two peaks at binding energies of 459.1 and 464.8 eV ascribed to TiO peaks, which signify the oxidation states of Ti that might have occurred during the hydrothermal process. , The peaks at 460.4 and 466.4 were associated with C–Ti–F peaks that F elements introduced during exfoliation through hydrofluoric acid, which was confirmed in FESEM EDX mapping in Figure …”

A photochemical approach to anchor Au NPs on MXene as a prominent SERS substrate for ultrasensitive detection of chlorpromazine

“…The morphologies of TiC and TiC/Au-NPs were investigated with the FESEM images at different magnifications. to Ti 2p 3/2 and Ti 2p 1/2 [24]. These two XPS peaks of Ti are observed with the splitting energy of 5.9 eV, which represents the presence of Ti in TiC.…”