A direct Z-scheme photocatalyst Bi2O3/MoO3 was prepared via hydrothermal method and mixing-calcination methods. The as-obtained Bi2O3/MoO3 composites exhibit higher photocatalytic activities than pure Bi2O3 and MoO3 for degradation of methylene blue (MB) under visible light irradiation. The increased photocatalytic activity is mainly attributed to the efficient separation of photogenerated charge carriers through a Z-scheme system between Bi2O3 and MoO3. Furthermore, the results of energy band positions, active species trapping experiments and photoluminescence spectroscopy (PL) provide direct evidence of an efficient Z-scheme as the main mechanism for degradation of MB under visible light irradiation over Bi2O3/MoO3 composites. (C) 2018 Elsevier B.V. All rights reserved.