LAUSR

Abstract Nowadays, the structural and functional deficiencies of ceramic membranes prepared by conventional approaches are of particular research of interest. In the present work, ceramic membrane was fabricated by constructing hierarchically structured separation layer on a porous alumina substrate. This layer was TiO 2 nano wires which synthesized by hydrothermal method followed by calcination at 550 °C to obtain the active anatase form. The synthesized TiO 2 nano wire was characterized by XRD, SEM, EDAX, TEM and UV–vis spectroscopy. The antibacterial activity of the synthesized TiO 2 nano powder was investigated against Escherichia coli bacteria by zone of inhibition test. To fabricate the ceramic membrane, the synthesized nano wire was sprayed on a porous sintered alumina substrate fabricated by gel-casting technique. Microstructure of TiO 2 /alumina ceramic membrane was investigated by SEM. XRD results revealed that the as-synthesized material at 200 °C was Na-titanate which transformed into H-titanate when neutralized with acid. After calcination at 550 °C, the formed phase was anatase nano wire. As indicated from TEM images, H-titanate long wires with 5–200 nm diameter and 5–25 µm length were obtained. After calcination, linear anatase nano wires with 10–50 nm thickness, 1–2 µm length and aspect ratio about 100 were detected. The TiO 2 nano wires exhibited bacterial activity toward E. coli with zone of inhibition equal 15 mm. Moreover, the fabricated alumina membrane had ideal microstructure which consists of three layers having gradual pore size and thickness. These layers were alumina support, interface layer, and TiO 2 nano wire layer.