Versatile Method for Preparing Two-Dimensional Metal Dihalides.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39106126.
- Also identified by DOI 10.1021/acsnano.4c04397 and PMC identifier 11342368.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ever since the ground-breaking isolation of graphene, numerous two-dimensional (2D) materials have emerged with 2D metal dihalides gaining significant attention due to their intriguing electrical and magnetic properties. In this study, we introduce an innovative approach <i>via</i> anhydrous solvent-induced recrystallization of bulk powders to obtain crystals of metal dihalides (MX<sub>2</sub>, with M = Cu, Ni, Co and X = Br, Cl, I), which can be exfoliated to 2D flakes. We demonstrate the effectiveness of our method using CuBr<sub>2</sub> as an example, which forms large layered crystals. We investigate the structural properties of both the bulk and 2D CuBr<sub>2</sub> using X-ray diffraction, along with Raman scattering and optical spectroscopy, revealing its quasi-1D chain structure, which translates to distinct emission and scattering characteristics. Furthermore, microultraviolet photoemission spectroscopy and electronic transport reveal the electronic properties of CuBr<sub>2</sub> flakes, including their valence band structure. We extend our methodology to other metal halides and assess the stability of the metal halide flakes in controlled environments. We show that optical contrast can be used to characterize the flake thicknesses for these materials. Our findings demonstrate the versatility and potential applications of the proposed methodology for preparing and studying 2D metal halide flakes.