Improvement of oxidative decomposition activity on hollandite type photocatalyst against pentachlorophenol

Abstract

Endocrine-disrupting chemicals such as pentachlorophenol (C6Cl5OH) are hazardous for the generative function of living creatures. Photocatalysts give us an effective route for removing these pollutants. Most of the reports are related to a photocatalyst of titanium dioxide (TiO2) fine particles loaded with metal particles such as Pt or Ag. However, a diversity of photocatalysts is required to deal with the increasing number of identified harmful chemicals which occur under a range of different conditions.Hollandites have one-dimensional tunnel-like framework structure. K2Ga2Sn6O16 (KGSO) is one of hollandite type compounds. In this study, hollandite type KGSO fine powders were fabricated using sol–gel method. The hydrolysis route was carefully observed for preparation of KGSO fine powders with high photocatalytic activity. To prepare the fine powder, the influence of hydrolysis temperature on preparation of fine powder was examined. It was found that the control of aforementioned temperature was very important for preparation of nano-sized KGSO powders with high activity. In addition, the authors controlled particle morphology of KGSO using different preparation conditions. The oxidative decomposition activity against C6Cl5OH on round shape KGSO nano-particles (78%) was much higher than that on the elongated shape KGSO particles (46.2%). It is concluded that the control of morphology and size of KGSO particles maximized the photocatalytic activity on KGSO for oxidative decomposition of C6Cl5OH. In addition, KGSO did not produce organic chlorides as by-products in the photocatalysis. Accordingly, it is expected that KGSO will be one of promising photocatalysts for decomposition of harmful aromatic compound C6Cl5OH under weak UV illumination.