Synthesis and photo-catalytic property of a hollandite-type compound (K 2Ga 2Sn 6O 16)

Abstract

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 K 2Ga 2Sn 6O 16 (KGSO). This compound has been shown to be catalytically active in the decomposition of endocrine-disrupting chemicals, pentachlorophenol (C 6Cl 5OH) and heptachloro-dioxin (C 12Cl 7O 2H), 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 C 6Cl 5OH and C 12Cl 7O 2H 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.