Micro-/nanostructured ZnFe2O4 hollow sphere/GO composite for structurally enhanced photocatalysis performance

The pollution of organic dyes has become a serious environmental problem. It is still urgent to prepare a highly efficient and environment-friendly photocatalyst for pollutants removal. Herein, a micro-/nanostructured ZnFe2O4 hollow sphere/GO (ZnFe2O4/GO) composite photocatalyst was prepared through a one-step hydrothermal method with high performance and recycling property. The obtained micro-/nanostructured composite was assembled by ZnFe2O4 hollow spheres and GO nanosheets. The special self-assembled hollow nanosphere structure enlarged visible light harvesting. In addition, luminescence property demonstrates that the introduction of graphene oxide (GO) inhibits the recombination of electron-hole pairs, leading to enhancement of photocatalytic activity of ZnFe2O4. Under visible light irradiation, the ZnFe2O4/GO composite exhibited excellent photocatalytic activity for Congo red (93%), higher than that of the pure ZnFe2O4 hollow spheres (only 60%) and commercial ZnFe2O4 nanoparticles (40%). Moreover, the micro-/nanostructured ZnFe2O4/GO composite photocatalyst can be regenerated with high efficiency and remains over 80% activity after seven regenerations. This work not only supplies a new strategy for one-step preparation of such ZnFe2O4/GO micro-/nanostructures for structurally enhanced photocatalysis, but also provides a highly efficient photocatalyst for wastewater treatment.