A versatile synthetic method, which is based on a low-temperature hydrothermal technique, is developed for the fabrication of a microporous ZnO/TiO2 composite catalyst with different structures (e.g., amorphous, amorphous/crystalline and crystalline). In particular, a novel microporous ZnO/TiO2 composite with amorphous/crystalline structure is obtained with a 3/1 M ratio of Ti/Zn. This novel ZnO/TiO2 composite heterostructure not only has a large specific surface area (311.9 m(2) g(-1)) but also exhibits outstanding performance during solar water splitting reactions to generate hydrogen without a noble metal co-catalyst. Based on our in-depth mechanistic analysis, the synergistic effect between the amorphous ZnO and crystalline TiO2 is responsible for the enhanced performance of this material. (C) 2013 Elsevier B.V. All rights reserved.