In this study, we investigate the effect of mixed surface terminations (F, O, OH) on the properties of MC MXenes (M = Sc, Ti, V). We explore how different compositions and patterns of terminal groups affect the stability and electronic properties of these 2D materials. The bond dissociation energies and cohesion energies show a clear preference for F-terminations in ScC, while Ti- and V-based MXenes prefer O-terminations. Our study is the first to demonstrate that terminal groups on opposite sides of the MXene have little to no influence on each other's electronic structure, allowing for independent chemical environments on each side. In a first of its kind investigation semiconducting forms of studied MXenes (ScCF, ScC(OH) and TiCO) showed very high sensitivity to conduction-inducing terminations (O, O, and F, respectively) with even minuscule amounts (≈1%) causing the materials to become conductive. This high sensitivity of the band gap to surface terminations may offer an explanation for the challenges in synthesizing semiconducting forms of MXenes.
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http://dx.doi.org/10.1039/d4cp01397b | DOI Listing |
Phys Chem Chem Phys
December 2024
Zhejiang Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201, China.
The electrochemical reduction of N to NH (NRR) is challenging due to the lack of efficient catalysts under mild conditions. We constructed a series of 3d-transition-metal (3d-TM)-embedded asymmetric 2D MXene HMoCF with one H or F vacancy (H or F) based on first-principles calculation. Due to the strong steric effect of the surface-covered H or F terminals, N is favored to be adsorbed on H or F through the end-on mode rather than the side-on mode.
View Article and Find Full Text PDFPhys Chem Chem Phys
October 2024
Department of Physics, Faculty of Science, University of Ostrava, 30. dubna 22, 701 03 Ostrava, Czech Republic.
In this study, we investigate the effect of mixed surface terminations (F, O, OH) on the properties of MC MXenes (M = Sc, Ti, V). We explore how different compositions and patterns of terminal groups affect the stability and electronic properties of these 2D materials. The bond dissociation energies and cohesion energies show a clear preference for F-terminations in ScC, while Ti- and V-based MXenes prefer O-terminations.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2024
Center of Excellence in Responsive Wearable Materials, Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330, Thailand.
The use of vanadium(V)-based materials as electrode materials in electrochemical energy storage (EES) devices is promising due to their structural and chemical variety, abundance, and low cost. V-based materials with a layered structure and high multielectron transfer in the redox reaction have been actively explored for energy storage. Our current work presents the structural and electrochemical properties of a vanadium-based composite with TiO@TiC MXene, referred to as VM.
View Article and Find Full Text PDFRSC Adv
July 2024
The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University Shanghai 200234 P. R. China
V-based materials are considered promising candidates as cathode materials for zinc ion batteries (ZIBs). However, the inherent low conductivity of V-based compounds leads to the sluggish diffusion kinetics of Zn and serious cycling capacity degradation of ZIBs. Herein, 1D ZnVO(OH)·2HO (ZVO) nanowires were grown on monodisperse 2D TiCT MXene nanosheets a facile microwave-assisted method.
View Article and Find Full Text PDFInorg Chem
July 2024
School of Physics, Harbin Institute of Technology, Harbin 150001, China.
Electromagnetic wave absorption performance is strictly dependent on attenuation and impedance matching, which are directly influenced by the ratio of MXene/MAX in the multilayer structured MXene/MAX composites. However, there is still a challenge to achieve collaborative optimization of dielectric loss and impedance matching by precisely regulating the proportional relationship of MXene/MAX. Herein, V-based MXene/MAX heterostructure composites with different VC/VAlC ratios were successfully synthesized by rationally controlling the temperature and time of the hydrothermal reaction.
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