Hydrothermal growth of free standing TiO₂ nanowire membranes for photocatalytic degradation of pharmaceuticals

• Published in: Journal of hazardous materials 2011-05, Vol.189 (1-2), p.278-285
• Main Authors: Hu, Anming, Zhang, Xu, Oakes, Ken D, Peng, Peng, Zhou, Y. Norman, Servos, Mark R
• Format: Article
• Language: English
• Subjects: annealing; Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Degradation; drugs; Exact sciences and technology; Folic Acid Antagonists; General and physical chemistry; Membrane separation (reverse osmosis, dialysis...); Membranes; microfiltration; microstructure; Nanocomposites; Nanomaterials; Nanowires; Nanowires - chemistry; Pharmaceutical Preparations - chemistry; Pharmaceutical Preparations - radiation effects; Pharmaceuticals; Phase Transition; photocatalysis; Photolysis - radiation effects; Pollution; Porosity; Reactors; solvents; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium; Titanium - chemistry; Titanium dioxide; trimethoprim; Trimethoprim - chemistry; ultraviolet radiation; Ultraviolet Rays
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.02.033

Highly entangled TiO₂ nanowires were directly synthesized by hydrothermal growth on Ti substrates at 180°C utilizing various organic solvents to oxidize Ti. The growth mechanism, microstructure and phase transition of TiO₂ nanowire membranes were investigated in detail. TiO₂ nanowires, with diameters of 10–20nm and lengths up to 100μm, show a phase transition from Type-B to anatase by annealing at 700°C. Robust, free standing TiO₂ nanowire membranes with millimeter level thickness can be cleaved from Ti substrates or directly prepared from thin Ti foils. These porous TiO₂ membranes, while effective for mechanical microfiltration, can also photocatalytically degrade pharmaceuticals such as trimethoprim under UV irradiation.