We report a simple method to fabricate well-aligned TiO2/SrO core/shell nanowire arrays. The core/shell structure is confirmed to have crystalline TiO2 nanowires core and amorphous SrO shell layer. The shell is composed of SrO with tunable thickness. Photocatalytic activity measurement shows that TiO2/SrO core/shell nanowire arrays outperform uncovered TiO2 nanowires. Such core/shell nanowire arrays have potential applications for photovoltaic devices and as high performance photocatalyst. (C) 2012 Elsevier Ltd. All rights reserved.