A flower-like CuO film on a Cu foil substrate has been synthesized via a facile one-step solution route at room temperature, using NaOH and (NH4)(2)S2O8 as raw materials. Formation mechanism of the flowerlike CuO assembled by nanosheets has been studied systematically based on series of control experiments. The optical property, photodegradation activity to a methyl blue (MB) solution and electrochemical sensing properties of the as-prepared flower-like CuO film have also been investigated. The experimental results support that the-flower-like CuO was formed underwent the following processes: Cu(OH)(2) nanorods *Cu(OH)(2) nanotubes CuO nanosheets flower-like CuO assembled by nanosheets. The flower-like CuO film exhibits an excellent photocatalytic activity to a MB solution with a high concentration. The electrochemical measurements show that the as-prepared flower-like CuO film can be used directly as a working electrode with a low detecting limit, good stability and selectivity to ascorbic acid (AA) solutions. (C) 2017 Elsevier Ltd. All rights reserved.