Combustion synthesis of magnetic Ag/NiFe2O4 composites with enhanced visible-light photocatalytic properties

Magnetic Ag/NiFe2O4 (ANFO) photocatalysts were synthesized by a one-step combustion method. The structures, morphologies, optical, magnetic, and visible-light photocatalytic properties of as-prepared ANFOs were characterized. Experimental results showed that cubic spinel NiFe2O4 and face-centered-cubic Ag were exclusively obtained. With increasing Ag content, red shift of the absorption edge and photoluminescence quenching were observed. The magnetic properties of ANFOs ensure the magnetic separation by using a magnet. ANFO with a mole ratio of Ag to NiFe2O4 of 0.04 shows the best visible-light photodegradation performance of methylene blue, which can be ascribed to the decrease in the energy band gap and the efficient transfer of photo-generated electrons from NiFe2O4 to Ag nanoparticles. Moreover, no obvious deterioration was observed the cycle photodegradation experiments. (C) 2014 Elsevier B.V. All rights reserved.