Improved hydrogen production from water splitting using TiO2–ZnO mixed oxides photocatalysts

TiO2–ZnO mixed oxides (1.0, 3.0, 5.0 and 10.0 wt.% Zn) photoconductors were prepared by the sol–gel method and used for the H2 production from water splitting. The solids were characterized by nitrogen physisorption, XRD, RAMAN, EDS, UV–Vis and XPS spectroscopy. High specific surface areas (85–159 m2/g) were obtained in all the mixed oxides compared to the bare TiO2 sample (64 m2/g). XRD and Raman spectra show that anatase is the predominant crystalline phase on the TiO2–ZnO solids. The band gap energy of the solids is in the interval from 3.05 to 3.12 eV which are in the same order than TiO2 (3.2 eV). These solids were proved in the photocatalytic water splitting and resulted six times more active (1300 μmol/h) than the reference TiO2 (190 μmol/h) semiconductor.