The recent development in one-dimensional materials leads to wide applications. One such material is 4–8 arsenene nanotube (4–8 AsNT), which possesses an energy band gap of 1.13 eV. Besides, the stable geometry of 4–8 AsNT is ascertained based on formation energy of −4.862 eV/atom. Furthermore, 4–8 AsNT is used as a base substrate to adsorb SF6 gas molecules and their decomposed constituents, namely SO2F2, and SOF2. The adsorption of SF6, SO2F2, and SOF2 shows physisorption nature on 4–8 AsNT, and the adsorption energy is recorded in the scope of −0.187 eV to −0.478 eV. The electron acceptor nature of 4–8 AsNT is exposed based on charge transfer and electron density difference results. The changes in the energy band are revealed from the band structure and PDOS (projected density of states) map due to SF6, SO2F2, and SOF2 molecular adsorption on 4–8 AsNT. Thus, the results support that 4–8 AsNT is a proper base material to detect SF6, SO2F2, and SOF2 leakage from the gas-insulated switchgear.