Putrescine adsorption on pristine and Cu-decorated B12N12 nanocages: A density functional theory study

Abstract

Putrescine (Put) adsorption on pure B12N12 and Cu-decorated (Cu– B12N12) nanocages was evaluated using density functional theory (DFT) calculations. Adsorption of copper on B12N12 results in two optimized geometries, named Cu@b66 and Cu@b64, with adsorption energies of approximately −2.01 and −2.07 eV, respectively. The results revealed that adsorption was a chemical process and adsorption energy decreased as follows: B12N12 > Cu@b64 > Cu@b66. DFT calculations indicated that the changes in gap energy (ΔEgap) of Cu@b66 (+16.28%) and Cu@b64 (+24.17%) were larger than that of B12N12 (−1.37%); so, Cu@b66 and Cu@b64 were more sensitive toward Put than pure B12N12. The changes in work function (ΔΦ) of the nanocages after interacting with Put increased as follows: B12N12 (23.33%) < Cu@b66 (34.21%) < Cu@b64 (41.97%), indicating that Put can be detected by the increase in electron current density of the nanocage–Put complexes. Quantum molecular dynamic reveal one interconversion from Cu@b66 to Cu@b64 with and without putrescine, implying that only Cu@b64 should be employed as potential conductometric and work function-type sensor for detecting of putrescine.