Discovery of Graphene‐Water Membrane Structure: Toward High‐Quality Graphene Process

Abstract

It is widely accepted that solid‐state membranes are indispensable media for the graphene process, particularly transfer procedures. But these membranes inevitably bring contaminations and residues to the transferred graphene and consequently compromise the material quality. This study reports a newly observed free‐standing graphene‐water membrane structure, which replaces the conventional solid‐state supporting media with liquid film to sustain the graphene integrity and continuity. Experimental observation, theoretical model, and molecular dynamics simulations consistently indicate that the high surface tension of pure water and its large contact angle with graphene are essential factors for forming such a membrane structure. More interestingly, water surface tension ensures the flatness of graphene layers and renders high transfer quality on many types of target substrates. This report enriches the understanding of the interactions on reduced dimensional material while rendering an alternative approach for scalable layered material processing with ensured quality for advanced manufacturing.

Salt-Catalyzed Directed Growth of Bilayer Palladium Diselenide (PdSe2) Dendrites and Pd Nanoparticle-Decorated PdSe2–Pd2Se3 Junction Exhibiting Very High Surface Enhanced Raman Scattering Sensitivity

“…During this process, a H 2 O film bridges the PdSe 2 layer to the inner edges of the mica and pulls it away from the mica surface. At the H 2 O/PdSe 2 interface, the driving force originates from the out-of-plane shear, where the shear stress is normal to the PdSe 2 surface. , Due to the high surface tension of H 2 O (72 mN m –1 ), the thin PdSe 2 film is successfully isolated and floated freely on the water surface. The H 2 O membrane stretches until the whole PdSe 2 layer is lifted from the mica surface.…”

Ultrahigh-quality graphene resonators by liquid-based strain-engineering

“…3(c)). 27,40,43,44 We conduct a scaling analysis of the strain-dependent changes in energy dissipation to identify the mechanism that limits the performance of the resonator.…”

Bioinspired 2D nanofluidic membranes for energy applications

“…87,88 Although graphene has many excellent properties, it lacks functional groups and has poor water solubility, which severely limits its application in the field of 2D functional membranes. [89][90][91][92] The exploitation of graphene derivatives is an effective solution to overcome the above limitations and expand their applications. For example, graphene oxide (GO) is formed by treating graphite with a strong oxidizing agent and adding epoxy, hydroxyl, and carboxyl groups to the basal surface of the graphite layer.…”