Photocatalytic Decolourisation of Orange II Aqueous Solutions by TiO_2 and ZnO Active Layers Screen Printed on Ceramic Tiles

摘要

In this work TiO_2 and ZnO layers have been deposited by screen-printing in common glazed ceramic tiles. These layers were evaluated for the photocatalytic degradation of Orange II in aqueous solutions, in a batch photoreactor under visible light. The photocatalytic behaviour was assessed by taking into account experimental variables which include: (ⅰ) firing temperature of the TiO_2 printed layer; (ⅱ) layer thickness; (ⅲ) operation time; (ⅳ) pH; and (ⅴ) dye concentration. Optimal processed layers showed an interesting decolourisation performance (over 90% efficiency after 7-8 h). It is anticipated that these new ceramic materials might be developed as an interesting alternative to TiO_2 or ZnO suspensions, for example in photocatalytic applications excusing the particles removal at the end of the process.