Density Functional Theory Study of Cu-Modified B(12)N(12) Nanocage as a Chemical Sensor for Carbon Monoxide Gas.

The development of efficient BN-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 BN results in five optimized structures, named CuBN and BNCu (doped structures), Cu@b and Cu@b (decorated structures), and Cu@BN (encapsulated structure). The results indicate that the CO gas weakly physisorbed on the BN nanocage. It was found that the gas adsorption performance of BN is improved due to the introduction of the Cu atom, but the interaction between CO and BNCu, Cu@BN, Cu@b, and Cu@b nanocages is strong, limiting the applications as a sensor. Particularly, the CuBN system shows moderate adsorption = -0.6 eV and a high electronic sensitivity Δ = 81.6% toward CO gas, compared to other modified systems. Furthermore, based on the sensor performance analysis, it was found that CuBN 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 CuBN as a superior sensor material for applications involving the selective detection of CO gas.