ABSTRACT Polycylonitrile (PAN) nanofiber webs containing titanium dioxide (TO2) were p via electrospin- ning Either dimethyl formamide (DMF) or its mixture with small amount of water (3 and 5%w was employed to prepare 5xw/w PAN/DMF or PANDMFHzo solution, respectively. Introducing non-solvent water in o solution was attempted to induce phase separation, which may lead to formation of porous structure on nanofibers surface. Different amounts of TO2 (1 to 3 wtx) were added into PANDMHH20) solutions and then electrospun into nanofiber webs. From SEM. nanofibers possessed rough surfaces and had averaged diameters in ranges of 170-430 nm.. showing tendency to increase with amount of Tio, and water. Porous structure on fiber surfaces was not clearly observed. which was suspected to be due to insufficient amount of water employed. Less homogeneity in poly solution due to presence of Tio, disfavored increasing water content higher 5xww. EDS data confirmed presence than of Tio, in electrospun webs. From photocatalysis evaluation. webs containing 2 and 3 wt.x To, showed good photocatalytic activity such that 80 percent of 10 ppm. methylene blue degraded in 24 hours. Sight increase in photocatalytic activity was observed in webs obtained from PANDMFH20 solutions. 2011 Elsevier BV. All rights reserved.