Magnetic Mesoporous Carbons Derived from in Situ MgO Template Formation for Fast Removal of Heavy Metal Ions

[Image: see text] In this paper, magnetic mesoporous carbon composites were prepared by calcination of the mixture of magnesium citrate and Fe(3)O(4)@SiO(2) in an inert atmosphere. A high content of Fe(3)O(4)@SiO(2) and MgO was in situ embedded in a carbon matrix. After removing the MgO template by diluted acid, the resulting material (Fe(3)O(4)@SiO(2)@mC) was subjected to further H(2)O(2) oxidation treatment. The formed oxygen-containing functional groups on the products provided plenty of active sites for the adsorption of analytes of interest. The obtained composites (Fe(3)O(4)@SiO(2)@mC-H(2)O(2)) exhibited a mesoporous structure with a high specific surface area of 731 m(2) g(–1). The adsorption capacities of Fe(3)O(4)@SiO(2)@mC-H(2)O(2) for Cu(II) and Pb(II) were calculated to be 86.5 and 156 mg g(–1), respectively. Under optimal conditions, the adsorption isotherm of Cu(II) and Pb(II) onto Fe(3)O(4)@SiO(2)@mC-H(2)O(2) fitted the Langmuir model and the adsorption kinetic was well-correlated with the pseudo-second-order model. Besides, Fe(3)O(4)@SiO(2)@mC-H(2)O(2) exhibited fast removal dynamics (within less than 1 min) for Cu(II) and Pb(II), demonstrating great application potential in wastewater treatment.