The role of CoTiO3 and the possible active species in the methylene blue (MB) degradation over the visible-light-driven CoTiO3/Ag3VO4 catalyst have firstly been investigated in this work. CoTiO3 is found to play important roles in enhancing the visible light-harvesting ability of the composite and increasing electron-hole separation efficiency due to the hybrid effect between Ag3VO4 and CoTiO3. The indirect probe experiments reveal that CoTiO3/Ag3VO4 heterostructure provides large amount of active species, therefore a high photocatalytic activity could be obtained. The results clearly suggest that the photocatalytic MB degradation over this hybrid catalyst is mainly governed by direct hole oxidation. (C) 2015 Elsevier Inc. All rights reserved.