Synthesis and photo-catalytic property of a hollandite-type compound (K2Ga2Sn6O16)

Hollandites crystallize with one-dimensional tunnel-like framework structures. The tunnels in the hollandite are usually occupied by alkaline or alkaline earth elements and a case in point is K2Ga2Sn6O16 (KGSO). This compound has been shown to be catalytically active in the decomposition of endocrine-disrupting chemicals, pentachlorophenol (C6Cl5OH) and heptachloro-dioxin (C12Cl7O2H), under weak ultraviolet illumination. It was observed that the morphology and size of the prepared materials was a significant factor in determining the extent of catalytic activity. Fine powders of KGSO were prepared using a sol-gel route. However, variations in the hydrolysis step allowed for control of the morphology of the produced, fine powders which in turn produced variations in the catalytic activity. The morphology of these powders was observed to be a key in maximizing the photocatalytic oxidative decomposition of both C6Cl5OH and C12Cl7O2H with particles which had a more rounded morphology having the greater activity. KGSO is a promising photocatalyst for decomposition of harmful aromatic compounds and with careful chemical control of its synthesis, the material can be optimized for chemical activity. (c) 2005 Elsevier Ltd. All rights reserved.