Two-dimensional crystal CuS—electronic and structural properties

Abstract

Covellite is a metallic layered mineral with rather strong interlayer interaction. Recently, synthesis of covellite nanosheets of 3.2 nm thickness was reported (Du et al 2012 Nat. Commun. 3 1177), which raises the question: 'What is the thinnest possible covellite nanosheet?' Based on density functional/ plane waves calculations, we have shown that graphene-like structure CuS (1L-CuS) is unstable but can be stabilized on a support. Here, however, we demonstrate that the three layered CuS (3L-CuS) with thickness of 0.773 nm (including the atomic radius of the outer plans atoms) is predicted to be intrinsically stable, as confirmed by phonon analysis and Born-Oppenheimer molecular dynamics simulations, with 3L-CuS about 0.15 eV per CuS less stable than the bulk. Interestingly, the electronic band structure shows metallic character with four bands crossing the Fermi level. The nature of chemical bonding is confirmed by a detailed topological analysis of the electron density.

Graphene‐Like Multilayered CuS Nanosheets Assembled into Flower‐Like Microspheres and Their Electrocatalytic Oxygen Evolution Properties

“…The S 2p 3/2 and 2p 1/2 peaks all can be fitted with two peaks at 161.3/162.2 and 163.2/164.0 eV, respectively. For the peaks of 161.3 (S 2p 3/2 ) and 163.2 eV (S 2p 1/2 ) are characteristic of sulfide, which should be attributed to the S−S bond in graphene‐like multilayered structure of CuS . The peaks at 162.2 (S 2p 3/2 ) and 163.2 eV (S 2p 1/2 ) are indicative of CuS, and the peak of 168.5 eV can be ascribed to the sulfate species (e. g. CuSO 4 ) formed by the oxidation of CuS in air .…”

“…More recently, Jr et al. demonstrated that monolayer CuS (1 L−CuS) was unstable according to their density functional/plane waves calculations, and the thinnest stable form of free‐standing stoichiometric CuS was predicted to be a three‐layered structure CuS of 0.773 nm thickness . It means that the CuS‐FSMs could possess unique performance in some field, but its synthesis is very difficult.…”

Room Temperature Wafer-Scale Synthesis of Highly Transparent, Conductive CuS Nanosheet Films via a Simple Sulfur Adsorption-Corrosion Method

“…Among them, the copper-deficient copper monosulfide (CuS) material shows particular promise as an impressive metallic candidate for various applications. [19][20][21][22] Theoretical studies indicate that the CuS possesses a graphene-like crystal structure with a P63/mmc space group and highly metallic conductivity perpendicular to the c-axis direction. Despite the large body of work on CuS nanosheets, there are still limitations with regards to the use of low temperature fabrication procedures, the scability of CuS nanosheet films, controlling the thickness and achieving high conductivity values close to the theoretical limit.…”

Transparent, Conducting Self‐Assembled CuS Nanostructures at and beyond Liquid‐Liquid Interface and their Electrocatalytic Properties

“…However, designing as well as fabricating such systems are challenging, and research in this direction is limited [1,6–8] . CuS is a semiconductor with layered structure but shows metallic conductivity due to the presence of a high density of holes [9,10] . CuS shows photo/electrocatalytic activity and offers high transparency in the visible region when the film thickness is low (<50 nm).…”

“…[1,[6][7][8] CuS is a semiconductor with layered structure but shows metallic conductivity due to the presence of a high density of holes. [9,10] CuS shows photo/ electrocatalytic activity and offers high transparency in the visible region when the film thickness is low (< 50 nm). Transparency decreases with increasing thickness.…”