Cu2O flower/grass-like nanoarchitectures (FGLNAs) were fabricated on a thin film of copper electrodeposited onto copper foils using a thermal oxidation method with a nickel catalyst at an elevated temperature under a moderately humid atmosphere. The morphology of the Cu2O FGLNAs can be controlled by the heating temperature, and the FLGNAs growth mechanism is discussed in detail. The photovoltaic effect of Cu2O/Cu junction based on fabricated Cu2O FGLNAs was also investigated. (C) 2014 Elsevier B.V. All rights reserved.