Hybridizing zero-dimensional nanoparticles with two-dimensional graphene oxide nanosheets has been regarded as one of the most promising way to improve the adsorptive and catalytic performance of nano materials. Graphene oxide-iron oxide (Fe3O4-GO) nanocomposites were synthesized using a co-precipitation combining hydrothermal method, and then characterized using XRD, TEM, BET, XPS and VSM to study their structures and functionalities. Fe3O4-GO was used to degrade phenol in a heterogeneous photo-Fenton process. The effects of different parameters, such as GO loading, catalyst dosage, initial concentration of H2O2 and initial pH of the phenol solution on the degradation efficiency were assessed. The results showed that under optimal conditions with UV-light irradiation, about 98.8% phenol and 813% TOC of a phenol solution could be removed after 120 min photo-Fenton degradation. It can be seen that UV-light improves significantly the phenol removal in photo-Fenton process. The introduction of GO in the catalyst promotes the photo-Fenton reaction via three roles: increasing adsorption capacity, offering more active sites and accelerating the Fe3+/Fe2+ cycle under UV light irradiation. It was also observed that Fe3O4-GO still showed high catalytic activity after five cycles. (C) 2016 Elsevier B.V. All rights reserved.