Novel 2D materials from exfoliation of layered hydroxide salts: A theoretical study

Highlights: • DFT calculations were performed for the investigation of the exfoliation of four layered hydroxide salts. • The structures of the exfoliated materials were explored. • The exfoliation energies were computed for the four materials. • The electronic structure of the bulk and the exfoliated structures were compared. • The effects of doping and dehydration on the electronic structure were also explored. -- Abstract: Using density functional theory (DFT), we theoretically investigated the electronic and structural properties of monolayer and few-layer 2D materials obtained from the exfoliation of zinc-based layered hydroxide salts (LHSs). Four different compounds are investigated: Zn₃(OH)₄(NO₃)₂, Zn₅(OH)₈Cl₂.H₂O, Zn₅(OH)₈(NO₃)₂.2H₂O and NaZn₄(OH)₆SO₄Cl.6H₂O. We found exfoliation energies in the range of 30 meV/Å̊² for all cases. Monolayer structures remained semiconducting like the respective bulk compounds, although in some cases, the band gap changes its character from indirect to direct. We also explored the effects of dehydration, which can also change the gap character from indirect to direct in some monolayer structures. Finally, we found that the anion or cation removal from the interlayer region can turn the monolayer systems into metallic, by means of electron and hole doping, respectively.