Efficient and scalable synthesis of highly aligned and compact two-dimensional nanosheet films with record performances

Abstract

It is crucial to align two-dimensional nanosheets to form a highly compact layered structure for many applications, such as electronics, optoelectronics, thermal management, energy storage, separation membranes, and composites. Here we show that continuous centrifugal casting is a universal, scalable and efficient method to produce highly aligned and compact two-dimensional nanosheets films with record performances. The synthesis mechanism, structure control and property dependence of alignment and compaction of the films are discussed. Significantly, 10-μm-thick graphene oxide films can be synthesized within 1 min, and scalable synthesis of meter-scale films is demonstrated. The reduced graphene oxide films show super-high strength (~660 MPa) and conductivity (~650 S cm−1). The reduced graphene oxide/carbon nanotube hybrid-film-based all-solid-state flexible supercapacitors exhibit ultrahigh volumetric capacitance (407 F cm−3) and energy density (~10 mWh cm−3) comparable to that of thin-film lithium batteries. We also demonstrate the production of highly anisotropic graphene nanocomposites as well as aligned, compact films and vertical heterostructures of various nanosheets.

Superhigh Electromagnetic Interference Shielding of Ultrathin Aligned Pristine Graphene Nanosheets Film

“…In our previous study, we reported a continuous centrifugal casting (CCC) method to synthesize highly aligned and compact two‐dimensional (2D) nanosheets films. [ 35 ] In the CCC method, the dispersion of 2D nanosheets is continuously cast/sprayed onto the inner surface of a rotating hollow tube (RHT) accompanied with low temperature heating. The alignment of 2D nanosheets is achieved by a shear force along the tangential direction of RHT, which is generated by the velocity difference between the tube and liquid, while the compaction is realized by a centrifugal force along the radial direction of the tube that is generated by high speed rotating.…”

Electromagnetic Shielding of Monolayer MXene Assemblies

“…Our theoretical analysis shows the importance of 2D nature of the metallic material for achieving multiple reflections and strong attenuation of electromagnetic waves. Also, considering that the conductivity of micron‐thick films of Ti 3 C 2 T x already exceeds 10 000 S cm −1 and further improvements are expected, more than 30 MXenes are already available and dozens more underway, there are exciting opportunities for further control of microwaves with ultrathin films of metallic 2D carbides and nitrides produced by scalable solution processing …”

Scalable Synthesis of Multifunctional Epidermis‐Like Smart Coatings

“…Concurrently, along with the increase of the contents of MTM nanosheets, the full width at the half maximum (FWHM) of dominant XRD peaks becomes smaller (Figure a,b). Similar results have been observed before in clay nanocomposites, indicating the better in‐plane alignment of 2D nanosheets . It is likely the presence of larger amounts of MTM nanosheets in the top layer poses additional spatial restriction for ordering so that the statistical distribution of in‐plane orientation is reduced (Figure c) as supported by simulations .…”