Photogeneration of hydrogen from industrial wastewater containing organic pollutants by using TiO2/ZrO2 nanocomposite

The simultaneous production of hydrogen and degradation of organic pollutants (methyl orange and cyanide ion) was successfully achieved using TiO2-10%ZrO2 photocatalyst which was synthesized in our previous study. With this catalyst, the degradation of methyl orange (or cyanide ion) was accompanied by the concurrent production of H2. The effects of operational variables, including pollutant concentration, solution pH and irradiation time, on the rate of hydrogen production were investigated. The activity of TiO2-10%ZrO2 gradually decreased with increasing pH, which makes its application of limited to the acidic pH region. The effect of concentration of the pollutants on the hydrogen generation rate is consistent with a Langmuir-Hinshelwood kinetic model. The enhanced photocatalytic activity could be explained in terms of reduced electron-hole recombination via hole consumption by pollutants. It is concluded that, under certain experimental conditions, it is possible to obtain significantly enhanced rates of photoinduced hydrogen production from TiO2-10%ZrO2 with simultaneous degradation of methyl orange and cyanide ion.