Synthesis of lanthanum oxide doped photocatalytic nano titanium oxide through aqueous sol-gel method for titania multifunctional ultrafiltration membrane

Abstract

An all aqueous sol gel route has been demonstrated for the synthesis of titania multifunctional ultrafiltration membrane on porous alumina substrate. Doping with lanthana was used to increase the thermal stability of anatase phase. This resulted in a nanoporous membrane with considerable percentage of anatase phase even after consolidation at 800A degrees C. The highly homogeneous membranes with a thickness of similar to 4-5 mu m could be observed in SEM. The presence of anatase phase ensured higher photoactivity for the doped membrane compared to the undoped one. The performance of the membrane was tested based on molecular weight cut off and a very high (> 90%) filtration efficiency was observed on Bovine Serum Albumin of molecular weight 66 kD. Rejection of 11 nm sized particles points to the uniform nanoporous nature of these highly efficient membranes.