Synthesis of TiO2 nanostructure membrane and influence of ZrO2 addition on microstructure, thermal stability and membrane properties

A method for the synthesis of crystalline TiO2 nanostructured membranes by the polymeric sol– gel technique is established. Macroporous α-alumina support was used as substrate and intermediate layer was obtained by deposition and calcination of the colloidal titania sol on the substrate. The influence of several processing variables on particle size and sol stability of titania was investigated. The effect of 20mol% zirconia doping on microstructure, liquid permeability, thermal and mechanical stability of composite titania/zirconia membranes was studied. The thermal and mechanical stability, phase transformation, surface morphology, pore size distribution and permeation of the defect-free titania-zirconia membrane were investigated by using X-ray diffraction(XRD), Atomic Force Microscopy (AFM), gas adsorption analyzer (BET), TG-DTA Analysis, scanning Electron Microscope(SEM), FTIR Analysis and water permeation apparatus, respectively.It was shown that zirconia retards the phase transformation of anatase to rutile until at least 700 oC. The pore size decreases to 1.2 nm by addition of up to 20 mol% zirconia, while nitrogen sorption experiments shows that the porosity, BET surface area and pore connectivity increases.