Preparation of Nanostructured Photocatalytic TiO ₂ Films and Membranes Using Sol-Gel Methods Modified with Surfactant Micelles for Wastewater Treatment and Reuse in Space

This study describes the application of novel chemistry methods for the fabrication of robust nanostructured TiO₂ photocatalytic films and membranes for the development of efficient wastewater treatment and reuse systems for advanced life support in space missions. These films and membranes perform several functions, including water purification (i.e., destruction of organic contaminants, filtration) and water disinfection. Nanocrystalline TiO₂ thin films and membranes, and the corresponding particles have been synthesized from a titania sol modified with nonionic long chain surfactants used as pore directing agents. The prepared materials were characterized to reveal material crystal structure, morphology, nanostructure, elemental composition, and other characteristics, and evaluated for their adsorptive properties and photocatalytic activity to destroy organic contaminants in water. The prepared TiO₂/Al₂O₃ composite membranes showed promising results with respect to water permeability and organic retention. These TiO₂ photocatalysts will be crucial components for the fabrication of integrated photocatalytic reactors and membranes for the low-temperature production of clean potable and hygienic water in space missions.