Photocatalytic hydrogen evolution over semiconductors is an efficient method for solar-energy conversion. Heterostructural photocatalysts with separated photoexcited carriers exhibit efficient photocatalytic hydrogen evolution without co-catalysts. In this study, heterostructures comprising of Cd1-xZnxS and Zn1-yCdyS phases were prepared through the replacement and sulfuration process at high temperature using Zn powders as the precursor. Highly crystalline Cd1-xZnxS-Zn1-yCdyS heterostructures without noble metal co-catalysts present a stable and highly effective photocatalytic hydrogen evolution rate under both UV-visible and visible-light irradiations due to the synergistic effects of Cd1-xZnxS and Zn1-yCdyS. (C) 2017 Elsevier B.V. All rights reserved.