Carbonaceous N-containing materials derived from leather skin residues have been found to have unprecedented photocatalytic properties as compared to P25 Evonik, with an interesting degradation potential for contaminants in water (e.g. phenol). The carbonaceous materials were prepared by carbonization of the leather skin residues at different temperatures (180-600 degrees C). Different crystalline species of Cr2O3 and TiO2 were found in the materials obtained. In spite of a low surface area and phase crystallinity, a thermally treated material at 180 degrees C containing doped chromium oxides (eskolaite phase) provided remarkably improved activities with respect to classical titania derived materials. (C) 2013 Elsevier B.V. All rights reserved.