Monolayer NbSe₂ Favors Ultralow Friction and Super Wear Resistance

Abstract

The urgent demand for atomically thin, superlubricating, and super wear-resistant materials in micro/nanoelectromechanical systems has stimulated the research of friction-reducing and antiwear materials. However, the fabrication of subnanometer-thick films with superlubricating and super wear-resistant properties under ambient conditions remains a huge challenge. Herein, high-quality monolayer (ML) NbSe 2 (∼0.8 nm) with ultralow friction and super wear resistance in an atmospheric environment was successfully grown by chemical vapor deposition (CVD) for the first time. Moreover, compared with few-layered (FL) NbSe 2 , ML NbSe 2 has a lower friction coefficient and better wear resistance. On the basis of density function theory (DFT) calculations, the adhesion and the degree of charge transfer between ML NbSe 2 and the substrate is larger than that of the topmost layer to the underlying layers of NbSe 2 with two or more layers, which can be used to explain that the ML NbSe 2 favors ultralow friction and super wear resistance.

Enhancing the Triboelectric Charges and Manipulating the Resistance of a Te Thin Film

“…Two-dimensional (2D) materials have great application prospects in the field of M/NEMS due to their ultrathin crystal structure, high mechanical strength, and excellent physical and chemical properties. − However, research on the micro- and nanoscale CE mechanisms based on 2D materials is currently limited due to the low amount of frictional charges generated and the subsequent difficultly in detecting and characterizing them. , Single-element 2D materials, such as graphene and black phosphorus (BP), offer novel research strategies for the CE mechanism owing to their simple and well-defined structures. − Some analysis was conducted on the macroscopic CE mechanism based on graphene. , The research on CE based on graphene is limited on the nanoscale mainly because graphene has a zero bandgap, which causes the charges generated by frictional electrification to dissipate easily . Additionally, the carbon atoms in graphene easily undergo oxidation–reduction reactions with the generated charges .…”

Accelerating Macroscale Superlubricity through Carbon Quantum Dots on Engineering Steel Surfaces

“…Friction and wear are ubiquitous mechanical motion phenomena that cause energy consumption and economic losses, and DOI: 10.1002/adfm.202310880 researchers are working to develop a series of lubricating materials with anti-friction and anti-wear properties. [1][2][3][4] Superlubricity refers to the lubricating state in which the friction coefficient is less than 0.01, making it possible to realize near-zero friction and near-zero wear, and is a feasible strategy to achieve the goals of carbon peak and carbon neutrality. [5][6][7][8][9][10] Solid superlubricity, based on 2D layered materials, such as molybdenum disulfide, [11][12][13] graphene, [14][15][16][17] and highly oriented pyrolytic graphite, [18] have been reported one after another.…”

Fundamental Limits of Few-Layer NbSe2 Microbolometers at Terahertz Frequencies

“…Layered van der Waals (vdW) superconductors have recently emerged as a convenient platform for investigating quantum phenomena arising in two dimensions and for future technology prototypes. − Among them, two-dimensional (2D) niobium diselenide (NbSe 2 ) is one of the most extensively studied compounds. − Not only has it enabled the observation of numerous spectacular effects ranging from high-critical-field Ising superconductivity and charged density waves − to unusual continuous paramagnetic-limited superconducting phase transitions and magnetochiral anisotropy, , but it has also given rise to several interesting applications such as superconducting diodes and rectennas . Despite significant progress in understanding the fundamental properties of this material via transport and optical experiments, − little is known about the response of NbSe 2 to terahertz (THz) radiation. − …”