Photocatalytic hydrogen production of CdS/ZnO shell/core nanoarrays were investigated by combining the sensitization and calcining techniques. Long single crystal ZnO nano arrays hydrothermally grown on FTO were fully covered with CdS using an optimized chemical bath deposition method. Heating treatment not only improved the interface connection and CdS crystallinity but also formed a (Cd0.8Zn0.2)S buffer layer between ZnO and CdS. The CdS/ZnO shell/core arrays showed gradually enhanced photocatalytic activity with raising the calcining temperature. This is predominantly attributed to the improved CdS crystallinity and the resultant (Cd0.8Zn0.2)S. The (Cd0.8Zn0.2)S buffer layer formed by calcining shows dramatic effect on the photocatalytic activity and stability. The CdS/ZnO shell/core arrays calcined at 550 degrees C exhibits the optimized photocurrent density of 5.1 mA cm(-2) and a photocatalytic stability over 12 h under visible-light irradiation. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.