Chinese scholars have made progress in new methods for the synthesis of two-dimensional materials

Figure Melt-assisted precipitation growth process mechanism, material classification and 80 kinds of ultra-thin two-dimensional single crystal and large-size films

With the support of the National Natural Science Foundation of China (grant numbers: 22171016, 21821004, 21932001), Professor Gong Yongji of Beijing University of Aeronautics and Astronautics and Professor Wu Kai of Peking University proposed a simple and efficient universal strategy for melt-assisted growth of two-dimensional materials, which realized the kinetic control
of the melt-assisted synthesis process 。 The research results, titled "Flux-assisted growth of atomically thin materials," were published online in Nature Synthesis on September 30, 2022
.
Links to papers: https://doi.
org/10.
1038/s44160-022-00165-7
.

Two-dimensional materials have attracted extensive attention
in recent years due to their special physical and chemical properties.
These atomic layer thickness materials provide an ideal platform for exploring catalytic, magnetic, superconductivity, and topological properties at two-dimensional limit scales, and controllable preparation of high-quality two-dimensional materials is a prerequisite
for their application.
Chemical vapor deposition (CVD) and mechanical peel (ME) methods have been widely used in the preparation of various ultra-thin materials, but these methods still face many challenges
.
For example, the traditional CVD method is prone to phase separation when synthesizing complex multivariate two-dimensional materials; For non-layered materials with strong bonding energy between crystal planes, it is difficult to be synthesized by CVD method and not easy to peel off
by ME method.

In view of this, in order to break through the limitations of traditional methods for synthesizing two-dimensional materials, the team of Professor Gong Yongji of Beihang University and the team of Professor Wu Kai of Peking University proposed a new universal strategy
for melt-assisted growth of two-dimensional materials.
Nearly 100 kinds of ultra-thin two-dimensional single crystal nanosheets were successfully prepared by using the melting and precipitation mechanism of classical growth single crystals, supplemented by kinetic control factors such as confined space and melt wettability (Fig.
).

The synthesis method accurately controls the composition of the product through a homogeneous molten phase, showing the potential for
the preparation of two-dimensional single crystal films.
Compared with traditional synthesis methods, melt precipitation has the advantages of high efficiency and stability, controllable components and high repeatability, especially has a high tolerance to external growth conditions (such as temperature, air flow size, number of precursors, etc
.
).
In addition, through microscopic atomic structure characterization and semiconductor, magnetic, superconductivity and ferroelectric performance tests, it is proved that the ultra-thin two-dimensional nanosheets synthesized by this method have high quality and excellent performance
.

Compared with the traditional methods that are difficult to controllably synthesize complex multi-layered or non-layered ultra-thin two-dimensional single crystal materials, this study breaks through the limitation of synthesizing ultra-thin materials, proposes a universal strategy for synthesizing two-dimensional materials, and provides new ideas
for the future synthesis of more complex multi-dimensional two-dimensional materials, non-layered two-dimensional materials and large-size single crystal films.