Post-synthetic particle size reduction of a layered cesium titanate (Cs2Ti5O11) for the improvement of photocatalytic H2 production

Layered cesium titanate (Cs 2 Ti 5 O 11 ) having an elongated rectangular particle shape of size a few hundreds of nanometers has been prepared by size reduction of a macroscopic sample prepared by a previously reported solid-state reaction procedure. The as-prepared material had a particle size of 3 μm (length) and 0.5 μm (width). The described size reduction was accomplished by first pelletizing the Cs 2 Ti 5 O 11 by pressing it in a mold, and then crushing it in a mortar. The Cs 2 Ti 5 O 11 samples before and after size reduction were proton-exchanged to obtain H 2 Ti 5 O 11 , which proved to be active for photocatalytic H 2 production in the presence of methanol as a sacrificial donor under UV irradiation. In this process, H 2 Ti 5 O 11 derived from size-reduced Cs 2 Ti 5 O 11 exhibited higher activity than that derived from the pristine Cs 2 Ti 5 O 11 . • Layered cesium titanate (Cs 2 Ti 5 O 11 ) having an elongated rectangular particle shape of size a few hundreds of nanometers has been prepared by size reduction of the as-prepared material. • The size reduction was successfully achieved by pelletizing of Cs 2 Ti 5 O 11 by pressing in a mold and subsequent crushing in a mortar. • The titanates were proton-exchanged to obtain H 2 Ti 5 O 11 . • Size-reduced H 2 Ti 5 O 11 exhibited higher activity than pristine H 2 Ti 5 O 11 by UV irradiation from aqueous methanol solution.