Ayoub Taavoni-Gilan - Assistant professor of nanomaterials engineering, Razi University
Ehsan Taheri-Nassaj - Associate professor of materials science and engineering, Tarbiat modares University,
Mojtaba Shamsipur - professor of analytical chemistry, Razi University,

Nanostructured TiO2/ZrO2 composite membranes with varying compositions were obtained by sol–gel technique. The influence of 0-30 mol% zirconia doping on microstructure, water permeability, photocatalytic and physical separation properties, removal of methyl violet of textile industries wastewater and thermal and mechanical stability of titania/zirconia composite membranes was described. Firstly, alumina supports were coated with TiO2 intermediate layers using the colloidal sol–gel route. The TiO2/ZrO2 composite sols were prepared via a polymeric sol–gel method and dip-coated on TiO2 intermediate layer. The samples were characterized by DLS, TG-DTA, XRD, FTIR, BET-BJH, UV-visible, SEM, TEM and AFM. It was shown that zirconia retards the phase transformation of anatase to rutile until at least 700 oC. The minimum pore size and maximum surface area have been obtained 1.2 nm and 153 m2/g, respectively that attributed to the sample with 20 mol% zirconia. The mechanical strength of titania membranes was significantly improved by addition of zirconia. The most methyl violet removal efficiency, with and without UV-irradiation, has been obtained 80.8% and 72.6%, respectively that attributed to the sample with 20 mol% zirconia.

Titania/zirconia membrane; Sol-gel method; Photocatalytic; Physical separation