Adsorption of COCl2 gas molecule on armchair boron nitride nanoribbons for nano sensor applications

• COCl2 molecule prefers to adsorb at the B-atom edge rather than N-atom edge.
• Adsorption at open edge is energetically more favorable than closed edge adsorption.
• Significant change in the electronic band structure of ABNNR is found after COCl2 adsorption.
• The enhanced current carrying capability of ABNNRs after COCl2 adsorption justifies its utility for sensors applications.

First-principle calculations under the framework of density functional theory have been performed to study the adsorption of COCl2 (Phosgene) gas molecule on armchair boron nitride nanoribbon (ABNNR). Depending upon the geometry of the ribbon, we have considered two possible cases for adsorption of guest molecule i.e. adsorption at closed edge and adsorption at open edge. Adsorption energy (Ead) calculations implies that adsorption at open edge is energetically more favorable compared to closed edge case. The formation of closed ring structure at the open edge in this case also accounts for its stability. Electronic properties reveal that with the adsorption of COCl2 molecule on ABNNR the semiconducting behavior remains intact but a significant modulation in the band gap is observed as compared to bare ribbon. The current voltage (I–V) characteristics have also been investigated using non-equilibrium green’s function (NEGF) approach. The results indicate towards the potential applicability of ABNNR for sensing the toxic COCl2 gas.

COCl2 adsorbed armchair boron nitride nanoribbon.Figure optionsDownload as PowerPoint slide