The preparation of the anatase and rutile forms of Ag-TiO2 and hydrogen production from methanol/water decomposition

This study examined hydrogen production over Ag-TiO₂ photocatalysts containing Ag_xO, a conducting component. X-ray photon spectroscopy (XPS) confirmed that the Ag and Ag₂O components were dominant in the Ag-TiO₂ photocatalysts treated at 500 and 800 °C, respectively. The Ti2p bands in Ag-TiO₂ were shifted to lower binding energies, which were assigned to Ti³⁺, compared to pure TiO₂, and the shift was greater in the rutile structure than in the anatase. The measured full widths at half maximum (FWHM) of the Ag3d and Ti2p peaks were larger in the anatase structure than in the rutile structure in both TiO₂ and Ag-TiO₂. The H₂ production from methanol photodecomposition was greater over the rutile structure than over the anatase structure of TiO₂. Moreover, the amount of hydrogen was enhanced over Ag-TiO₂ compared to pure TiO₂; the production reached 17,124 μmol after 24 h over rutile Ag-TiO₂. After methanol photodecomposition, the amount of Ag component in the Ag-TiO₂ photocatalysts increased, while the Ag₂O component decreased.