The possibility of obtaining foam-like copper (I) oxide and the process of carbon dioxide photocatalytic reduction under its participation were studied. It was shown that this material had a high photocatalytic activity in gas phase CO2 reduction with water vapor to acetaldehyde (up to 8.2 mu mole.g(cat)(-1).h(-1)) and methane (up to 19.2 mu mole.g(cat)(-1).h(-1)). A similar effect can be explained both by the formation of nanocrystalline Cu2O and the spatial organization of such components into the foam-like three-dimensional (3D) material. Based on the distribution of the final products conclusions about the possible mechanism of CO2 conversion during a transition from an irradiation with the full spectrum of a lamp to UV and visible light were made. (C) 2016 Elsevier Ltd. All rights reserved.