Successful Immobilization of Lanthanides Doped TiO 2 on Inert Foam for Repeatable Hydrogen Generation from Aqueous Ammonia

摘要

We describe the successful possibility of the immobilization of a photocatalyst on foam, which is beneficial from a practical point of view. An immobilized photocatalyst is possible for use in a continuous experiment and can be easily separated from the reactor after the reaction concludes. Parent TiO 2 , La/TiO 2 , and Nd/TiO 2 photocatalysts (containing 0.1 wt.% of lanthanide) were prepared by the sol-gel method and immobilized on Al 2 O 3 /SiO 2 foam (VUKOPOR A) by the dip-coating method. The photocatalysts were investigated for the photocatalytic hydrogen generation from an aqueous ammonia solution under UVA light (365 nm). The evolution of hydrogen was compared with photolysis, which was limited to zero. The higher hydrogen generation was observed in the presence of 0.1 wt.% La/TiO 2 than in 0.1 wt.% Nd/TiO 2 . This is, besides other things, related to the higher level of the conduction band, which was observed for 0.1 wt.% La/TiO 2 . The higher conduction band’s position is more effective for hydrogen production from ammonia decomposition.