Formation of sandwich structured ZnCe0.03Fe1.97O4@nSiO2@SBA-15 and adsorptive removal of methylene blue from aqueous solution

Sandwich-structured ZnCe0.03Fe1.97O4@nSiO2@SBA-15 (mSBA-15A) was fabricated in the present conditions. The sample showed a rod-like shape with uniform mesochannels. The pore size, pore volume and surface area of the sample were determined to be about 5.4 nm, 0.53 cm3/g, and 481 m2/g, respectively. Compared pore size, pore volume, and surface area with magnetic mesoporous SiO2 as listed in Table 1, the mSBA-15A is more suitable as an adsorbent for wastewater treatment. And it can be used as an adsorbent in acidic solution, such as 1.0 mol/L HCl aqueous solution. The maximum adsorption capacity for methylene blue (MB) was determined to be 241 mg/g, which is higher than some references reported. Langmuir model was employed to fit the adsorption isotherm, which implied the single layer adsorption. The adsorption process can be described by the pseudo-second-order model.