Development of TiO2-coated YSZ/silica nanofiber membranes with excellent photocatalytic degradation ability for water purification
Jin Young Huh, Jongman Lee, Syed Zaighum Abbas Bukhari, Jang‐Hoon Ha, In‐Hyuck Song
Abstract
Abstract Numerous reports have elucidated that TiO 2 nanoparticles (TiO 2 -NPs) exhibit respectable photocatalytic degradation capacities due to their high specific surface areas. However, the current recovery process leads to a loss of TiO 2 -NPs; therefore, there is a need to immobilize TiO 2 -NPs on the substrate used. Herein, TiO 2 -coated yttria-stabilized zirconia/silica nanofiber (TiO 2 -coated YSZ/silica NF) was prepared by coating TiO 2 on the surface of YSZ/silica NF using a sol–gel process. The TiO 2 coating layer on the nanofiber surface improved the separation ability of the membrane as well as the photocatalytic degradation ability. The pore size of the TiO 2 -coated YSZ/silica NF membrane was less than that of the pristine YSZ/silica NF membrane, and it rejected over 99.6% of the 0.5 μm polymeric particles. In addition, the TiO 2 -coated YSZ/silica NF membrane showed excellent adsorption/degradation of humic acid (HA, 88.2%), methylene blue (MB, 92.4%), and tetracycline (TC, 99.5%). Six recycling tests were performed to evaluate the reusability of the TiO 2 -coated YSZ/silica NF membrane. The adsorption/degradation efficiency for HA, MB, and TC decreased by 3.7%, 2.8%, and 2.2%, respectively. We thus verified the high separation ability, excellent photocatalytic degradation ability, and excellent reusability of the TiO 2 -coated YSZ/silica NF membranes.