Facile inverse micelle fabrication of magnetic ordered mesoporous iron cerium bimetal oxides with excellent performance for arsenic removal from water.

In this study, magnetic ordered mesoporous Fe/Ce bimetal oxides (OMICs) were successfully synthesized via the modified sol-gel-based inverse micelle method. The textural/structure properties, surface chemistry and adsorption behavior of OMICs could be easily adjusted by using the calcination temperature. The sintering of samples would decrease the surface area, while expand the pore and crystallite size, which resulted in the formation of highly ordered inner-connected structure. Compared with pure mesoporous iron oxides (MI) and mesoporous cerium oxides (MC), this ordered mesoporous iron-cerium bimetal oxides (OMIC-3, 450 °C) exhibited remarkable arsenic adsorption performance. The maximum adsorption capacities of As(III) and As(V) for OMIC-3 were 281.34 and 216.72 mg/g, respectively, and both As(III)/As(V) adsorption kinetics were well described by the pseudo-second order. The ionic strength and coexisting ions (except SiO and PO) did not affect arsenic removal, while humic acid (HA) significantly influenced on the arsenic removal even at a lower concentration. The adsorption mechanism study revealed that both the surface charge and surface M-OH groups of OMIC-3 were played the key roles in arsenic removal. The reusable property suggested that this magnetic OMIC-3 was a promising excellent adsorbent for decontamination of arsenic-polluted (especially As(III)-polluted) wastewater.