Controlling the flake size of bifunctional 2D WSe₂ nanosheets as flexible binders and supercapacitor materials

Abstract

A new approach using graphene as a conductive binder in electrical supercapacitors has recently been produced. Graphene shows outstanding properties as a conductive binder, and can be used to replace...

Mild Liquid-Phase Exfoliation of Transition Metal Dichalcogenide Nanosheets for Hydrogen Evolution

“…All of the (002) peaks are more pronounced with ultrasound treatment, and almost all of the other peaks have vanished, indicating the success of TMD exfoliation. , Figure h,i shows the Raman spectrum of WSe 2 and MoSe 2 , respectively. The bulk WSe 2 has two distinct strong peaks at 251 and 256 cm –1 , corresponding to the (in-plane) and A 1g (out-of-plane) modes, while the two strong peaks of the bulk MoSe 2 are located at 241.6 and 284.1 cm –1 . All of the full width at half-maximum of nanosheets’ peaks is found to increase and A 1g modes’ redshift supports the success of exfoliating. , The same trend can also be observed in WS 2 and MoS 2 (Figure j,k).…”

“…10,39 Figure 1h,i shows the Raman spectrum of WSe 2 and MoSe 2 , respectively. The bulk WSe 2 has two distinct strong peaks at 251 and 256 cm −1 , corresponding to the (inplane) and A 1g (out-of-plane) modes, 40 while the two strong peaks of the bulk MoSe 2 are located at 241.6 and 284.1 cm −1 . 41 All of the full width at half-maximum of nanosheets' peaks is found to increase and A 1g modes' redshift supports the success of exfoliating.…”

A Review: Ion Transport of Two-Dimensional Materials in Novel Technologies from Macro to Nanoscopic Perspectives

“…Examples include the capacitive behavior of metallic electrodes and of two-dimensional (2D) materials such as graphite, graphene and transition metal dichalcogenides (TMDs) family. These concepts should assist the development of the electrochemical devices (also refer to the electrochemical system) i.e., energy storages [6,25,26], capacitive deionization [27], 2D-based membrane (electrochemical ions sieving) [9,[28][29][30], and ion transport controls [31][32][33].…”

“…The theory of minimum space charge capacitance (C sc(0) ) can be calculated using the semiconductor model if we assume that the potential drop in capacitance inside the solid behaves like a semiconductor, as shown in Equation (5). Considering the effect of potential dependence, the space charge capacitance can be also calculated using Equation (6), where ε r refers to the solid phase (e.g., in the graphite a-b plane ε r = 2.61, along the crystallographic c-axis ε r = 3.28), c is the electronic charge carrier density (~4 × 10 18 carriers cm −3 ), and ϕ i is the potential at the surface of the electrode [38]:…”

“…By combining a number of membranes with highly packed selectively ionic channels, electric eels can produce a strong current density which can discharge up to 600 Volts [3]. Ion transportation can be used as a potential way of understanding the mechanism involved in order to explore the mimicking effect of artificial membranes for various ion transport-based applications such as film-based catalysts for gas production (hydrogen and oxygen evolution reactions) [4,5], energy storages (capacitors and batteries) [6][7][8], and membranes for ionic and molecular separation [9][10][11]. Instead of artificial membranes in living cells, ions transport can also relate to cell stabilities, helping us to understand the fundamental mechanisms of ion transport in vitro and in vivo [12].…”