Computational molecular design to assist modification of single – walled carbon nanotubes with B, N, Al, Si, P, and S dopant atoms for Cl2 gas sensor application

•Cl2 adsorption on SWCNT and doped SWCNT has been investigated by DFT-D4.•Pristine (4,0) SWCNT was less sensitive toward Cl2 gas.•Cl2 gas could be adsorbed on (4,0) SWCNT stably through B, Al, and Si doping.•Cl2 interacts strongly with B, Al, Si-doped SWCNT, according to NBO, QTAIM, NCI-RDG. Chlorine (Cl2) gas is toxic to humans. Exposure to this gas can cause skin and eye irritation, suffocation, and even death if a person is continuously exposed to Cl2 gas at high concentrations. Therefore, it is necessary to develop a detection sensor to minimize its impact. In this study, pristine Single-Walled Carbon Nanotubes (SWCNT) and SWCNT doped with Boron (B), Nitrogen (N), Aluminum (Al), Silicon (Si), Phosphorus (P), and Sulfur (S) dopant atoms were tested as sensors for Cl2 gas detection. The results show that the reaction between SWCNT and Cl2 gas is exothermic and occurs spontaneously. The bond distance formed between the Cl and B atoms in B-doped SWCNT is the shortest compared to other systems. The addition of B dopant atoms can also improve the electronic properties of the SWCNT. Furthermore, the addition of Al and Si atoms as dopants to the SWCNT also resulted in a high adsorption activity. From these results, it was concluded that B, Al, and Si dopants were the most effective dopants used to enhance the sensitivity of SWCNT to chlorine gas. [Display omitted]