Large-scale and single-crystalline anatase TiO2 nanorods were synthesized via hydrothermal reaction of H-titanate fibers. It was found that the pH plays an important role in the shape and crystal structures of the products by hydrothermal post-treatment of H-titanate fibers in acidic solutions. At pH 2-7, the pure anatase phase was formed and the samples reserved the rod-like morphology with a diameter of 20-200 nm, in contrast to the formation of particles with a mixture of rutile and brookite phases at pH 0. Photocatalytic experiments indicated that the obtained single-crystalline anatase TiO2 nanorods are highly active for photodegradation of organic pollutants. Furthermore, we demonstrated that these nanorod catalysts can be easily recycled without decrease of the photocatalytic activity. (c) 2006 Elsevier B.V. All rights reserved.