Novel g-C3N4 decorated Bi2O4 heterojuction photocatalysts were prepared via a hydrothermal method. The obtained samples were characterized by using XRD, SEM, EDS mapping, FT-IR, XPS and DRS. After the introduction of g-C3N4, g-C3N4 nanostructure was evenly distributed on Bi2O4 nanorods, forming heterojunction composites with staggered band alignments. The photocatalytic performance was evaluated by the degradation of methyl orange under visible light irradiation. The g-C3N4/Bi2O4 composites exhibited significantly enhanced photocatalytic activity. Among them, 10CB sample displayed the highest degradation efficiency, whose apparent rate constant was 2.2 and 11.8 times higher than that of Bi2O4 and g-C3N4, respectively. Besides, by combining Bi2O4 with g-C3N4, the composites showed decent photochemical stability. It was assumed that the enhanced photocatalytic activity and photostability could be ascribed to the formation of heterojunction, which effectively promoted the separation and transfer of photogenerated charge carriers. (C) 2017 Elsevier Ltd. All rights reserved.