Novel magnetic semiconductor Na 2 Fe 2 Ti 6 O 16 : synthesis, double absorption and strong adsorptive ability

A multifunctional material, Na 2 Fe 2 Ti 6 O 16 (NFTO), was synthesized via a simple hydrothermal method for the first time. NFTO nanosheets with a long hexagonal plate shape enjoy double absorption, high magnetic moment and strong adsorption. The magnetic property allows for the convenient collection of the NFTO adsorbent from aqueous solution during recycling and double absorption in the visible-light region could be applied in visible-light harvesting. The double absorption and magnetic property originate from the d–d transitions of Fe 3+ , due to the effect of the crystal field. The adsorption process was evaluated by a methylene blue removal experiment and was found to have good agreement with the pseudo-second-order kinetics model and Langmuir isotherm. The NFTO nanosheets exhibit excellent recyclability, a high kinetic adsorption rate and a maximum adsorption capacity of 165.8 mg g −1 at equilibrium pH. These results are greatly significant for multifunctional NFTO as a promising adsorbent material used in water purification.