Diethylene Glycol-Assisted Organized TiO₂ Nanostructures for Photocatalytic Wastewater Treatment Ceramic Membranes

• Main Authors: Rizwan Ahmad, Jin Kyu Kim, Jong Hak Kim, Jeonghwan Kim
• Format: Article
• Language: English
• Published: MDPI AG 2019-04-01
• Series: Water
• Subjects: diethylene glycol; photocatalytic membrane; antifouling; photodegradation; nanostructure
• Online Access: https://www.mdpi.com/2073-4441/11/4/750

A high-performance photocatalytic ceramic membrane was developed by direct growth of a TiO₂ structure on a macroporous alumina support using a hydrothermal method. The morphological nanostructure of TiO₂ on the support was successfully controlled via the interaction between the TiO₂ precursor and a capping agent, diethylene glycol (DEG). The growth of anatase TiO₂ nanorods was observed both on the membrane surface and pore walls. The well-organized nanorods TiO₂ reduced the perturbation of the alumina support, thus controlling the hydrolysis rate of the TiO₂ precursor and reducing membrane fouling. However, a decrease in the amount of the DEG capping agent significantly reduced membrane permeability, owing to the formation of nonporous clusters of TiO₂ on the support. Distribution of the organized TiO₂ nanorods on the support was very effective for the improvement of the organic removal efficiency and antifouling under ultraviolet illumination. The TiO₂ nanostructure associated with the reactive crystalline phase, rather than the amount of layered TiO₂ formed on the support, which was found to be the key to controlling photocatalytic membrane reactivity. These experimental findings would provide a new approach for the development of efficacious photocatalytic membranes with improved performance for wastewater treatment.