Multifunctional photocatalytic performances of recyclable Pd-NiFe2O4/reduced graphene oxide nanocomposites via different co-catalyst strategy

In this report, magnetically recyclable, multifunctional Pd-NiFe2O4/reduced graphene oxide (Pd-NiFe2O4/rGO) photocatalysts have been successfully prepared by a one-step green hydrothermal method. The integration of NiFe2O4 with Pd nanoparticles supported on rGO enables efficient harvesting visible light for different catalytic reactions on the heterojunction structures. The Pd-NiFe2O4/rGO nanocomposites present significantly enhanced photocatalytic activity toward dyes degradation compared to the blank-NiFe2O4 and the optimum binary NiFe2O4/rGO, which is ascribed to the added Pd nanoparticles, acting as the mediator on the interfacial layer between NiFe2O4 and rGO, and transferring the charge carrier across the heterojunction interface. Another important role of Pd nanoparticles is as the electron reservoir, which can directly trap photogenerated electrons. It is interesting that the photogenerated electrons, which transfer to Pd nanoparticles, can increase the electron density of Pd. The energetic Pd nanoparticles thus raise their intrinsic catalytic activity, which can promote the Suzuki coupling under visible light irradiation. A possible catalytic mechanism for the multifunctional efficient photocatalytic performances is proposed. (C) 2016 Elsevier B.V. All rights reserved.