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

Abstract

Layered cesium titanate (Cs2Ti5O11) 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 Cs2Ti5O11 by pressing it in a mold, and then crushing it in a mortar. The Cs2Ti5O11 samples before and after size reduction were proton-exchanged to obtain H2Ti5O11, which proved to be active for photocatalytic H2 production in the presence of methanol as a sacrificial donor under UV irradiation. In this process, H2Ti5O11 derived from size-reduced Cs2Ti5O11 exhibited higher activity than that derived from the pristine Cs2Ti5O11.