Preparation of helical TiO2/CMC microtubes and pure helical TiO2 microtubes

• Published in: Journal of materials science 2004-04, Vol.39 (8), p.2663-2674
• Main Authors: MOTOJIMA, S, SUZUKI, T, NODA, Y, HIRAGA, A, YANG, S, CHEN, X, IWANAGA, H, HASHISHIN, T, HISHIKAWA, Y
• Format: Article
• Language: English
• Subjects: Anatase; Catalysis; Catalysts: preparations and properties; Catalytic activity; Chemical vapor deposition; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Chemistry; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; General and physical chemistry; Heat treatment; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Morphology; New materials: theory, design, and fabrication; Organic chemistry; Other materials; Photocatalysis; Physics; Sol-gel processes; Specific materials; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium dioxide; Tubes; Ultraviolet radiation; Vapor phases
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/B:JMSC.0000021440.04191.02

Helical TiO2/CMC (carbon microcoils) microtubes and helical TiO2 microtubes were obtained by making TiO2 layer coatings on the surface of CMC templates using a sol-gel and chemical vapor deposition (CVD) processes. The preparation conditions, morphologies and some properties were examined. Uniform TiO2 (anatase) layers were obtained on the CMC templates by a CVD process using vapor phase hydrolysis of titanium tetra-isopropoxide at 300°C followed by heat treatment in N2 or by calcination in air at 500–;650°C. The helical TiO2/CMC microtubes showed good photocatalytic activity. It was considered that the helical structure activated and enhanced the photocatalytic activity of TiO2, probably caused by the generation of inductive microelectric current induced by the irradiation of UV light, resulting in the generation of micromagnetic fields around the tubes.