Chromate ions chemisorption over the exterior surface of pristine boron nitride (B12N12) nanocage: A computational study.

[Display omitted] • Boron nitride nanocage (B 12 N 12) is explored as an efficient adsorbent for the removal of chromate ions from water using DFT simulations. • The structural optimization reveals that the chromates ions are strongly anchored onto the surface of B 12 N 12 nanocages which leads to stronger adsorption energies. • The thermodynamic parameters i.e. ΔH and ΔG shows that the adsorption process is spontaneous and feasible at ordinary temperature. • The atom in molecule, reduced density gradient and non-covalent interaction analysis evidenced the formation of covalent O B and N H hydrogen bonds between the adsorbate and adsorbent. In present study, we for the first time investigated boron nitride (B 12 N 12) nanocage as adsorbent material for removal of chromate species Cr(VI) from water using density functional theory simulations. The geometry optimization reveals that Cr(VI) strongly interact with the surface of B 12 N 12 nanocage. The bonding analysis shows that Cr(VI) species make strong intermolecular hydrogen bonds and chemical bonds with the exterior surface of B 12 N 12 nanocage. This stronger interaction leads to larger adsorption energies for different complexes ranging from −27.17 to −168.96 kcal/mol. Moreover, the computed thermodynamic values i.e. ΔH and ΔG are negative (ranging from −55.54 to −156.42 kcal/mol and from −47.31 to −151.21 kcal/mol, respectively) which reflects their feasible and spontaneous adsorption. Furthermore, a large amount of charge transfer between Cr(VI) and B 12 N 12 nanocage, resulting strong electrostatic interactions. The HOMO-LUMO gap is strongly reduced after the adsorption of chromate ions on the B 12 N 12 nanocage surface indicating a strong sensitivity of adsorbent. The AIM, RDG and NCI analyses evince the existence of stronger intermolecular hydrogen and chemical bond between the B 12 N 12 surface and chromate ions. The outcomes of the present study demonstrate that the B 12 N 12 nanocage could be used as an efficient adsorbent for purification of water from toxic pollutants. [ABSTRACT FROM AUTHOR]