Enhanced photocatalytic activity of TiO2-incorporated nanofiber membrane by oxygen plasma treatment

In this paper, we report on the high-performance photocatalysis of polymeric TiO2 membranes modified by oxygen plasma treatment for water purification. TiO2-nanopowder-incorporated poly epsilon-caprolactone (PCL/TIO2; PT) nanofibers were prepared by electrospinning at various concentrations of TiO2 (1,3,5, and 7 wt.%) and then treated by atmospheric plasma with oxygen gas (OAP). As the TiO2 content increased, the surface roughness and photocatalytic efficiency of the nanofibers increased. The tensile strength of the membranes increased until the TiO2 content reached 3 wt.% but led to a degradation of the mechanical property at higher concentrations owing to significant agglomeration of TiO2. The hydrophilicity of OAP membranes increased as the TiO2 nanopowders were exposed and the production of polar species was induced at the surface of the PT nanofibers. The OAP-PT membranes were observed to enhance the degradation of harmful organics. The results indicate that OAP-PT membranes are useful photocatalysts for purifying water. (C) 2011 Elsevier B.V. All rights reserved.