Hydrogen Production from Photocatalytic Splitting of Water/Methanol Solution over a Mixture of P25-TiO2and AgxO

A photocatalyst which mixed by the commercialized P25-TiO2 and a synthesized AgxO was used in an appropriate weight ratio to effectively produce hydrogen gas in this study. The AgxOs were synthesized with the conventional sol-gel method, and tetramethylammonium hydroxides were added at the synthesis process in order to stabilize the solutions, and then the solutions were heat-treated at the temperatures of -5, 25, and 50 °C, resulted to obtain the three types of silver oxides. Physicochemical properties of the synthesized AgxOs were identified through X-ray diffraction analysis (XRD), scanning emission microscopy (SEM), ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). In the photolysis results of water/methanol (weight ratio 1:1) solution, the mixture of P25-TiO2/AgxO exhibited a significantly higher hydrogen gases evolution, compared to that of pure P25-TiO2. Additionally, the addition of H2O2 as an supplement oxidant and in AgxO synthesized at 50 °C improved the hydrogen production efficiency. In particular, the emitted hydrogen gases reached to 13,000 μmol during 8 hours when a mixed catalyst, AgxO of 0.1 g and P25-TiO2 of 0.9 g, were used.