Low temperature synthesis of few-layer titanate nanobelts on Ti mesh and the hot-water induced transformations to highly photocatalytic active titania nanorods

Abstract

An efficient photocatalytic reactor to remove pollutants from either water or air relies on highly active photocatalytic thin films on appropriate substrates, which contribute to both light harvesting and pollutant molecules transfer. In this investigation, few-layer titanate nanobelts were deposited on metallic Ti mesh using hydrogen peroxide solution, which were then subjected to a subsequent hot water treatment to achieve crystallized titania nanorod arrays. The three-dimensional arrays of nanorods formed on Ti mesh (three layers overlapped) exhibited an exceptional high efficiency when utilized to assist photodegradation of rhodamine B in water under UV light illumination, which is 25 times that of P25 film, and even 1.3 times that of P25 nanoparticles in a slurry system. For photodegradation of phenol in water, the three-layer Ti mesh also exhibited a reaction rate constant 6.9 times that of P25 film. The reduced band gap, abundant surface hydroxyl groups, and mixed phase effects arising from the low temperature approach contribute to the high photocatalytic activity.