Photocatalytic and optical properties of nanocomposite TiO2-ZnO thin films S.H. Mohamed, M. El-Hagary and S. Althoyaib Eur. Phys. J. Appl. Phys., 57 2 (2012) 20301 Published online: 30 January 2012 DOI: 10.1051/epjap/2012110312