First principles study on the adsorption of lead ions by black phosphorus in aqueous solution.

In this paper, the adsorption behavior of intrinsic black phosphorus (BP) and BP doped with five atoms of O, Si, S, Cu and Zn on Pb 2 + in aqueous solution was investigated by using the first principle of nature. The formation energy was calculated to be the smallest for Si-doped BP at 2.608 eV, indicating the best structural stability. The adsorption energy was calculated and showed that the doped BP is more capable of adsorbing Pb 2 + than the intrinsic BP, with the S-doped BP having the strongest adsorption capacity of 0.151 eV. The density of states was calculated and showed that the bandgaps of the doped BP are all smaller than the 1.3 eV of the intrinsic BP, indicating that the doping can improve electrical conductivity of the adsorption system. The charge transfer was calculated and showed that S doping, O doping, Cu doping and Zn doping enhanced the ionic bonding between BP surface atoms and Pb 2 + , while Si doping weakened the ionic bonding. The charge transfer of S doping was the largest at 1.371 e, indicating that S-doped BP had the strongest ability to adsorb Pb 2 + . [ABSTRACT FROM AUTHOR]