The energy storage of TiO2 NiO/TiO2 film was proved by electrochemical process and photocatalytic activity for the first time. The film, prepared by spin coating, consisted of two layers. The first layer was TiO2, prepared from commercial titanium dioxide, while the second one was Ni(OH)(2) incorporated into TiO2. Ni(OH)(2) was subject to 300 degrees C calcination temperature and mixed with TiO2 sol before incorporation with TiO2. Acid orange 7 (AO7) in KPH/HCl buffer (pH = 3) was used for both electrochemical process and photocatalytic activity testing of the film. The TiO2-NiO/TiO2 film showed catalytic activity even without illumination implying that the energy stored during the illumination drove the reaction when there was no illumination. (C) 2016 Elsevier B.V. All rights reserved.