Post-Ammonia-Treated V₂CT_x MXene at Different Pressures: Effects on Morphology, Electronic, and Optical Properties

Abstract

In the present work, vanadium carbide (V 2 CT x ) MXene was synthesized successfully and then treated with an ammonia solution (NH 4 OH) under different pressures using a hydrothermal process. The sample morphology reveals that the V 2 CT x MXene gradually changed from uneven multilayered micrometre-size sheets to uniform few-layered nanometer-size sheets as the pressure increased. The optical emission spectra show broad emission and a blue shift due to nitrogen-related defects and quantum confinement. X-ray photoelectron spectroscopy shows the presence of nitrogen in all of the samples. The ultraviolet photoelectron spectroscopy study shows a modified density of states near the Fermi level and a maximum of ∼0.6 eV valence band edge shift towards a higher binding energy side after post-treatment with ammonia. More interestingly, the E 1g Raman band becomes degenerate and the E 1g band upshifts (∼15 cm −1 ) with increasing pressure treatment. The Raman results suggest that the induced lattice strain due to post-ammonia treatment plays a crucial role in deciding the optical and electronic properties.

Fluorine‐Free MXenes: Recent Advances, Synthesis Strategies, and Mechanisms

“…Reaction ( 46) plays a crucial role in eliminating the Al layers from the original Ti 3 AlC 2 structure. The reactions (47) and (48) lead to the introduction of ─O and ─OH terminations on the surface of the 2D IE-MXene, whereas ( 49) and ( 50) reactions outline a process where aluminum iodide reacts with water to form aluminum hydroxide and hydrogen iodide in the first reaction. leading to the formation of 2D MXene sheets.…”

“…[15][16][17]24,[43][44][45] Besides Ti 3 C 2 T x , the MXene family encompasses a wide variety of potential constituents such as Ti 2 CT x , Nb 2 CTx, Mo 2 CT x , V 2 CT x , and numerous additional members. [46][47][48][49][50][51][52][53][54][55] The MXenes such as (Ti,Nb) 2 CTx, (Ti,V) 2 CT x , (V,Nb) 2 CT x , mixed transition metals MXenes like, TiVNbMoAlC 3 and TiVCrMoAlC 3 , have also been observed. [19,56] Despite their inherent hydrophilicity, MXenes have exhibited superior electrical conductivity compared to graphene produced through simple solution processing.…”

Improved Surface-Enhanced Raman Scattering Performance of 2D Ti3C2Tx MXene Embedded in PVDF Film Enabled by Photoinduction and Electric Field Modulation

“…Apart from other 2D materials, MXenes are newly discovered carbides, nitrides, and carbo nitrides which gained a lot of attention due to their unique electrical, mechanical, and optical properties. 27,28 The strong localized SPR (LSPR) of MXene makes it suitable for SERS application. 29−34 After the discovery of MXene in 2011 by Gogotsi et al, Ti 3 C 2 T x was largely studied among several other MXenes like V 2 CT x , Nb 2 CT x , Ti 2 CT x , Ti 2 NT x etc.…”

Strain and charge doping effect in MoS2 sheets decorated with AgFeO2 particles

“…14 Strain leads to a change in electronic band structure and hence drastically affect the aforementioned properties of 2D materials. [15][16][17][18][19][20] Existing research cites that by strain modulation, one can engineer the properties of 2D materials. Theoretically, it was predicted that $2% of strain in MoS 2 can lead to transition from direct to indirect band gap material while $10% of strain may show semiconductor to metallic transition.…”

“…The occurrence of strain in low‐dimensional materials can cause lattice deformation 14 . Strain leads to a change in electronic band structure and hence drastically affect the aforementioned properties of 2D materials 15–20 . Existing research cites that by strain modulation, one can engineer the properties of 2D materials.…”