We examined the carbon adsorption parameters (adsorption
time, pH value of the solution, reaction temperature and lead(Ⅱ) ion
concentration) systematically and the obtained results are illustrated
in the supplemental materials. The Pb@C materials used in
this study were the products obtained in the optimum conditions,
which are labeled as PAC1, PAC2, PAC3 and PAC4, respectively, according
to the raw carbons used. The Pb@C materials were
performed by X-ray diffraction patterns (XRD) using a BRUKER D8
ADVANCE X-ray diffraction analyzer (Germany) with Cu Ka radiation
(l ¼ 0.15406 nm) at 300 mA and 5.0 kV and scanning electron
microscope (SEM) and energy dispersive spectrometer (EDS) examinations
using an environmental scanning electron microscope(China)) was employed to measure the content of the main metal
elements.
ZEISS ULTRA55 (Germany). Atomic Absorption Spectroscopy (AAS