Potential of nanostructured carbon materials for iodine detection in realistic environments revealed by first-principles calculations.

In the context of effective detection of iodine species (I 2 , CH 3 I) formed in nuclear power plants and nuclear fuel reprocessing facilities, we perform a comparative study of the potential sensing performance of four expectedly promising 2D materials (8- Pmmn borophene, BC 3 , C 3 N, and BC 6 N) towards the iodine-containing gases and, with the view of checking selectivity, towards common inhibiting gases in the containment atmosphere (H 2 O and CO), applying methods of dispersion-corrected density functional theory with periodic boundary conditions. A covalent bond is formed between the CO molecule and boron in BC 3 or in 8- Pmmn borophene, compromising the anticipated applicability of these materials for iodine detection. The presence of nitrogen atoms in BC 6 N-2 prevents the formation of a covalent bond with CO; however, the closeness of adsorption energies for all the four gases studied does not distinguish this material as specifically sensitive to iodine species. Finally, the energies of adsorption on C 3 N yield a significant and promising discrimination between the adsorption energies of (I 2 , CH 3 I) vs. (CO, H 2 O), revealing possibilities for this material's use as an iodine sensor. The conclusions are supported by simulations at finite temperature; underlying electronic structures are also discussed.