CoFe2O4@ZnS core-shell spheres as magnetically recyclable photocatalysts for hydrogen production

CoFe2O4@ZnS core-shell nanoparticles were used as hydrogen production photocatalysts, which can be recycled by magnetic force for repeated hydrogen generation. Magnetic CoFe2O4 nanoparticles were used as core materials. The ZnS shell layer is synthesized with zinc acetate and thiourea as precursors by a solvothermal process. The morphology, crystalline property, surface area, magnetic property, photocatalytic H-2 production performance, and magnetic recycling capability of the photocatalysts were investigated. Effects of ZnS shell growth time (ZnS shell thickness) and calcination treatment on the photocatalytic activity were studied. Calcination helps to improve the photocatalytic activity. The H-2 production rate of CoFe2O4@ZnS-0.5h photocatalyst calcinated at 500 degrees C reached 1650 mu mol/g h. The photocatalysts can be effectively recycled by an external magnet. Recycled photocatalysts exhibit good hydrogen generation performance after being recycled for three times. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.