Synthesis and characterization of , and hydrogen production from methanol photodecomposition over the mixture of and

This study focused on the production of hydrogen from the methanol destruction in a liquid photocatalytic system that comprised a mixture of Ag_xO and TiO₂ (P-25, Degussa). The nanometer particles of Ag_xO were obtained by a conventional sol–gel method in the presence of tetraethylammonium hydroxide using thermal treatment at 50, 100, 150, 200, 250, and to attain various silver oxide forms. The 38.0 and 43.0 peaks, which were assigned to Ag₂O and Ag metal, respectively, were seen in Ag_xO powder at each temperature; however, these Ag₂O/Ag ratios varied and the AgO form was not found in any of the samples. In the XPS data, the peak which was assigned to Ag3d_5/2 in the Ag metal or Ag₂O was present in all the Ag_xO samples. In particular, the peak of Ag3d_5/2 in the Ag metal was dominant at high temperature, while the peak of Ag3d_5/2 in Ag₂O increased at low temperature. When TiO₂ was used as a photocatalyst in the methanol photodecomposition reaction, no hydrogen gases were evolved. However, the hydrogen product was remarkably increased in the mixture of Ag_xO and TiO₂ photo-system. Moreover, it was more enhanced when Ag_xO thermally treated at was added, compared to the samples with Ag_xO thermally treated at other temperatures, and the production peaked at 17,000 μmol after 24 h.