Recent Developments on Emerging Properties, Growth Approaches, and Advanced Applications of Metallic 2D Layered Vanadium Dichalcogenides

Abstract

The electronic structures of transition metal dichalcogenides (TMDs) has a strong dependency on the d‐band electrons of the central metal (M) atom. In particular, trigonal prismatic coordinated (2H) and octahedral coordinated (1T) phases with distinct crystal structure‐property relationships. Extraordinarily diverse electrical properties ranging from semiconducting, semimetallic to intrinsic metallic basically underlie from different Fermi level locations. Amid all TMDs, most specifically metallic VX2 possess plenty of interesting physical properties among them superconductivity, electrical conductivity, charge density wave, optical and magnetism etc. have offered intriguing applications in the fields of condensed matter physics, materials and device physics over the last few decades. Further modification of these materials by defect engineering, Li intercalation, electron beam/light irradiation, alloying and dimensional tuning can lead several tunable device applications. Due to their superior mechanical flexibility, controllable electrical properties, planar fabrication and high surface to volume ratio etc., 2D metallic TMDs materials emerge as active material for sensing, energy storage, conversion and field emission applications. This review article aims to provide the insights on the recent developments of different emerging properties, growth approaches and applications of 2D metallic VX2 (X = S, Se and Te) and its heterojunctions.

2D Metallic Transition‐Metal Dichalcogenides: Structures, Synthesis, Properties, and Applications

“…The hydrothermal method is a bottom–up synthesis method using water as the reaction medium to obtain high‐yield ultra‐thin 2D m‐TMDs. [ 238 ] In Figure a, the reactants, water, and surfactants are mixed at room temperature and then placed in a sealed container. The temperature of the reaction system must be higher than the boiling point of the solvent, which can promote the generation of high pressure and further improve the crystallinity of m‐TMDs.…”

1T-VS2/MXene Hybrid as a Superior Electrode Material for Asymmetric Supercapacitors: Experimental and Theoretical Investigations

“…A broad class of materials having a formula MX 2 (where M represents the transition-metal element of group IV or V or VI and X represents the chalcogen, i.e. , S or Se or Te atom). , Their extraordinary features like tunable electronic properties, unusual physiochemical (thickness-controlled), optical (tunable band gap), high mechanical strength, and so on, particularly, mono- and multi-layered TMDs hold great opportunity to explore in a variety of applications . Owing to these excellent properties, TMDs have been explored in a wide variety of applications such as in supercapacitors, , batteries, , energy conversion, , sensors, catalysis, field emission, photovoltaic, and electronics and optoelectronic devices. , The M–X possesses strong covalent bonds to be arranged in the X–M–X layered morphology, while weak van der Waals interaction dominates between two MX 2 layers featuring two-dimensional (2D) layered like structures .…”

Vertically Aligned Graphene‐Analogous Low‐Dimensional Materials: A Review on Emerging Trends, Recent Developments, and Future Perspectives

“…Nonstoichiometric 2D materials with curved edge structures are critical for the intrinsic magnetic and spin-dependent properties. [84][85][86][87] Theoretical studies demonstrated that the magnetic properties in TMDs such as MoS 2 , VS 2, and VSe 2, etc. arise from the unsaturated transition metal and S/Se atoms at the edges.…”

“…arise from the unsaturated transition metal and S/Se atoms at the edges. [87][88][89][90][91] Hence, the vertically aligned 2D layered materials are ideal candidates for tunable magnetic properties due to the presence of an abundant number of open edges and defects on its surface. Vertically aligned edges of MoS 2 nanobelts showed room-temperature ferromagnetic properties with the magnetization of 0.055 emu g −1 at an applied field of 1T, which was ≈50 times larger than that of solution exfoliated MoS 2 .…”

“…Field emission is the phenomenon of electron ejection by quantum mechanical tunneling from a material with the application of a very high electric field in ultravacuum conditions. [87] Vertically aligned 2D nanostructures have emerged as high-performance field emitter cathode material due to their exceptional tunable electronic properties, the sharp nanometric dimension with planar structure, and protruding edges of sheets with dangling bonds. Li et al presented the field emission functionalities of vertically standing MoS 2 nanosheets.…”