Studies of hydrogen sulfide and ammonia adsorption on P- and Si-doped graphene: density functional theory...

Studies of hydrogen sulfide (H₂S) and ammonia (NH₃) adsorption on phosphorus (P) and silicon (Si) doped graphene are performed by ab initio calculations using the periodic density functional theory (DFT). The P and Si incorporation in graphene distorts the unit cell altering the bond lengths and angles. Unlike the pristine, the phosphorus-doped graphene shows a metallic behavior, and the silicon-doped graphene is a semiconductor with an energy gap of 0.25 eV. Moreover, the electronic properties of phosphorus-doped graphene may change with the adsorption of hydrogen sulfide and ammonia. However, the silicon-doped graphene only shows changes with the adsorption of hydrogen sulfide. In addition, the silicon-doped graphene exhibits chemisorption when interacting with ammonia. According to the obtained results, phosphorus-doped graphene is suitable as a gas sensor of hydrogen sulfide and ammonia, in contrast with the silicon-doped structure, which may be used as a sensor of hydrogen sulfide. Graphical Abstract Ammonia adsorption on Si-doped graphene.