Visible light active zeolite-based photocatalysts for hydrogen evolution from water

Hydrogen, considered as the fuel for future can be produced from non-conventional, renewable and plentiful source like water. Novel zeolite-based materials that show photocatalytic properties in the visible light have been synthesized by incorporating titanium dioxide (TiO2), heteropolyacid (HPA) and transition metals like cobalt (Co). These materials show high efficiency for water splitting under visible light irradiation. Hydrogen (H2) generation to the tune of 2730 μmol/h/g TiO2 has been obtained for the composite photocatalyst synthesized. Platinum (Pt) doping has also been attempted in this composite photocatalyst, however, no substantial enhancement in hydrogen generation was observed. The high efficiency of the composite photocatalyst suggests that the TiO2 which gets effectively dispersed and stabilized on the surface of zeolite works synergistically with transition metal like cobalt and heteropolyacid to make the material active in visible light for photoreduction of water to hydrogen. The aluminosilicate framework of zeolite also contributes towards delayed charge separation. This composite photocatalyst shows improvement in hydrogen evolution rate over other TiO2 based visibly active photocatalyst reported.