Recent progress in plasma-assisted synthesis and modification of 2D materials

Abstract

Plasma represents an important technique for both the synthesis and modification of two-dimensional (2D) materials, owing to the unique plasma-material interactions which can enable effective energy transfer at the nanoscale. Non-equilibrium and non-thermal plasma techniques have been widely applied on various 2D materials, including graphene, silicene, germanene, phosphorene, hexagonal boron nitride (h-BN), and transition metal dichalcogenides such as MoS2 and WS2. Here, we review the recent progress in plasma-assisted synthesis and modification (e.g. functionalisation, doping and etching) of 2D materials and discuss the potential applications of this unique branch of 2D materials. Challenges and future research opportunities in the relevant research field are also discussed. The primary aim of this Review is to provide a better understanding of the plasma-assisted processes and to promote the utilization of 2D materials for advanced electronic, optoelectronic, sensing and energy storage applications.

Modulating Schottky Barrier of MoS2 to Enhance Hydrogen Evolution Reaction Activity by Incorporating with Vertical Graphene Nanosheets Derived from Organic Liquid Waste

“…The VGNS/MoS 2 shows the smallest with the value of 3.8 , much lower than that of MoS 2 (5.4 ) and Ni foam (99.3 ), implying a faster electron transfer between the active sites and the electrode substrate . It may be attributed to the decease of the Schottky barrier ( ) on catalyst/electrode interface owing to the in‐situ growth of VGNS on current collector, as well as the strong electronic interaction between MoS 2 and VGNS with high conductivity ,. The electrochemically active surface area (ECSA) is estimated by measuring the double‐layer capacitance ( ) via cyclic voltammetry (CV) test at different scan rates (Figure S8).…”

“…However, non‐sustainable and explosive petroleum gases like CH 4 and C 2 H 2 are normally required to synthesize VGNS, which renders an extra high cost of production and potential risk of safety management . In present work, we innovatively employed organic liquid waste sourced from various chemical processes in petroleum‐based industry (e. g., fuels, lubricants and pumping fluids, solvent) as carbon precursor to fabricate VGNS, with the conception of waste valorization . By interaction with the versatile active species (excited molecules, ions, radicals, etc.)…”

“…[18] In present work, we innovatively employed organic liquid waste sourced from various chemical processes in petroleum-based industry (e. g., fuels, lubricants and pumping fluids, solvent) as carbon precursor to fabricate VGNS, with the conception of waste valorization. [21][22][23] By interaction with the versatile active species (excited molecules, ions, radicals, etc.) and energetic electrons in non-thermal plasma, waste organic liquid could be converted into VGNS in a facile and controllable manner.…”

“…[33] It may be attributed to the decease of the Schottky barrier (� SC ) on catalyst/electrode interface owing to the in-situ growth of VGNS on current collector, as well as the strong electronic interaction between MoS 2 and VGNS with high conductivity. [22,35] The electrochemically active surface area (ECSA) is estimated by measuring the double-layer capacitance (C dl ) via cyclic voltammetry (CV) test at different scan rates ( Figure S8). The value of C dl is calculated from the half value of linear slope indicated in Figure 3e.…”

Few-layer flakes of Molybdenum Disulphide produced by anodic arc discharge in pulsed mode

“…[10][11][12] The cited materials can be obtained by means of different synthesis techniques, such as chemical or mechanical exfoliation of bulk material, [13] and plasma processing of a gaseous precursor. [14] Anodic arc discharges constitute very efficient plasma sources of nanomaterials, as initially proven by the seminal work by Iijima on the production of carbon nanotubes from plasma ablation of a graphite anode. [6] The high gas temperatures reached in the carbon arc column provide appropriate conditions for synthesis of carbon crystalline nanostructures.…”