The electrochromic, photodegradation, and photoinduced hydrophilicity properties of the WO3/TiO2 core-shell nanostructure as a smart building material for energy-saving are investigated. The core-shell nanostructure exhibits a highly reduced ion intercalation capacity with good reversible electrochemical cycling of intercalation-deintercalation, and shows a higher coloration efficiency (110.8 cm(2) C-1), faster switching speed (0.7 s and 2.9 s) and better cycling performance than as-deposited WO3 nanowires (NWs). The TiO2 shell layer greatly enhanced the photocatalytic oxidation activity of WO3 NWs, increasing the photoinduced hydrophilic conversion. The enhanced photocatalytic reaction by the core-shell structure was attributed to the multi-electron reduction in the interlayer, caused by the electrons injected from the conduction band of the WO3 NWs. These results suggest that the WO3/TiO2 core-shell nanostructure enhances the electrochromic, photodegradation, and photoinduced hydrophilicity properties due to the increased density of charge separated electron-hole pairs aided by the TiO2 and WO3 interlayer. The WO3/TiO2 core-shell structure was found to possess superior properties giving it good potential for use in energy-saving smart windows. (C) 2014 Elsevier B.V. All rights reserved.