Preparation and its application of TiO2/ZrO2 and TiO2/Fe photocatalysts: A perspective study

Abstract

The preparation and application of TiO2/ZrO2 and TiO2/Fe photocatalysts were reviewed. We have prepared TiO2/ZrO2 and TiO2/Fe photocatalyst by sol-gel process for degradation of phenolic compounds, decolourization of dye solution and removal of heavy metals in the wastewater. ZrO2/TiO2 composite photocatalytic was produced on the pure titanium substrate using in situ Zr(OH)4 colloidal particle and the ZrO2/TiO2 composite shows a lamellar and porous structure which consists of anatase, rutile and ZrO2 phases by the micro-arc oxidation technique. TiO2 doped with Fe produced by the sol-gel method using titanium alkoxide as the precursor of titania as well as iron as dopant sources. Among synthesized photocatalysts, 0.1 M Zr and 0.15 M N supported on TiO2 exhibited the best visible-light response and the highest NO photodegradation activity. The photocatalysts calcined at 500°C are spherical particles with a crystallite size about 10-20 nm and the crystal phase presents a mixture of anatase (dominant phase) and rutile. The optimum doping amount of iron ions is 0.001 mol %. Although the addition of iron ions decreases the surface area of Fe/TiO2, the photocatalytic activity of Fe/TiO2 (i.e., 0.001 mol %) is better than those of synthesized bare TiO2 or P25. Consequently, the role of Fe may be responsible for the enhanced photodegradation, as compared to those from P25 or synthesized bare TiO2.