Density Functional Theory Study of Cu-Modified B12N12 Nanocage as a Chemical Sensor for Carbon Monoxide Gas.

Abstract

The development of efficient B12N12-based toxic gas sensors has received considerable attention from the scientific community. Thus, in this regard, quantum chemical calculations were performed using density functional theory (DFT) at the B97D/6-31G(d,p) level for all of the studied systems. Modification of copper on B12N12 results in five optimized structures, named CuB11N12 and B12N11Cu (doped structures), Cu@b66 and Cu@b64 (decorated structures), and Cu@B12N12 (encapsulated structure). The results indicate that the CO gas weakly physisorbed on the B12N12 nanocage. It was found that the gas adsorption performance of B12N12 is improved due to the introduction of the Cu atom, but the interaction between CO and B12N11Cu, Cu@B12N12, Cu@b64, and Cu@b66 nanocages is strong, limiting the applications as a sensor. Particularly, the CuB11N12 system shows moderate adsorption (Eads = -0.6 eV) and a high electronic sensitivity (ΔEgap = 81.6%) toward CO gas, compared to other modified systems. Furthermore, based on the sensor performance analysis, it was found that CuB11N12 presented low recovery time (14 ms) and high selectivity for CO detection, making it a promising fast response sensor. Finally, our results demonstrated the capability of CuB11N12 as a superior sensor material for applications involving the selective detection of CO gas.