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 AgxO, 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.