Heterogeneous photo-Fenton catalysts generally show very weak photo-Fenton activity at near-neutral pH because of the relatively low rate of Fe2+ regeneration. The aim of this work is to develop novel heterogeneous photo-Fenton catalysts, which can accelerate the regeneration of Fe2+ and thus have superior photo-Fenton activity at near-neutral pH. In this study, ferrihydrite (Fh) was modified with BiVO4 to synthesize BiVO4/Fh composites, and we expected that the photogenerated electrons from BiVO4 would accelerate the regeneration of Fez' on Fh. Mechanistic investigation of H2O2 consumption showed that the introduction of BiVO4 promoted the decomposition of H2O2 into reactive oxygen species (ROS). In addition, the presence of BiVO4 deterred O-2(+) production and accelerated the formation of " OH, according to the results of ROS formation, as shown with EPR spectroscopy and fluorescent probes tools. Furthermore, the Fez' concentration on the surface of BiVO4/Fh was higher than that on Fh based on the results of XPS characterization and quantitative measurement with a 1,10-phenanthroline spectrophotometric method. These results demonstrated that the introduction of BiVO4 can accelerate the reduction of Fe3+ to Fez' by transferring photogenerated electrons from BiVO4 to Fe3+ on the surface of Fh. Meanwhile, a higher decolorization efficiency of acid red 18 by BiVO4/Fh than by Fh and pure BiVO4 verified that the introduction of BiVO4 can significantly enhance the photo-Fenton catalytic activity of Fh even at near-neutral pH. Overall, our work has important implications for understanding the photo-Fenton mechanisms on semiconductor modified heterogeneous photo-Fenton catalysts and confirms that the introduction of a semiconductor can enhance the photo-Fenton catalytic activity of heterogeneous photo-Fenton catalysts in acidic and neutral pH. (C) 2017 Elsevier B.V. All rights reserved.