Few-layered boron nitride nanosheets as superior adsorbents for the rapid removal of lead ions from water
- 79 Downloads
Newly few-layered boron nitride (BN-550) nanosheets were developed by a low-temperature synthesis method, which was used to rapidly and efficiently adsorb lead ions (Pb2+). The samples were characterized by using XRD, FT-IR, EELS, SEM, TEM, AFM and XPS, revealing that it possessed the large specific surface area (696 m2 g−1), ultrathin sheet structure (1.2 nm thickness), and abundant chemical bonds as multiple adsorption sites. The adsorption properties showed that higher adsorption capacity (845 mg g−1) for lead ions and less equilibrium time (15 min) than many adsorbents reported at present. The adsorption kinetics and isotherms of BN-550 belonged to the pseudo-second-order model and Langmuir model, respectively. The easy recyclability and stability of BN-550 were verified by the experiments regeneration and pH. Interference experiments indicated that the adsorbents were strong affinity for Pb2+ under the interference of other heavy metal ions such as Ni2+, Cu2+, and Cd2+ ions (their adsorbing capacity individually are 201, 402, and 312 mg g−1). The XPS and FT-IR analysis revealed that the excellent adsorption performances for Pb2+ attributed to the chemical binding reactions with the numerous surface functional groups, such as the strong B–O–Pb interactions and –NH2···Pb complex. The threshold value of Pb2+ removal on BN-550 nanosheets was 1080 mL g−1 when Pb2+ concentration was 50 mg L−1 in adsorption column. The unique characteristics render ultrathin nanosheets highly promising as an ideal candidate for the removal of lead ions.
This work was supported by the Natural Science Foundation of China (21277146), the Key Technologies R & D Program Foundation of Anhui Province (1704a0802136), the Chinese academy of sciences key deployment project (KFZD-SW-309), the CASHIPS Director’s Fund (YZJJ201701) and the Young Spark Project Foundation of CASHIPS (YZJJ201617).
- 52.World Health Organization (2011) Guidelines for drinking-water quality, 4th edn. World Health OrganizationGoogle Scholar