Au-decorated Na(x)H(2-x)Ti(3)O(7) nanobelts exhibiting remarkable photocatalytic properties under visible-light illumination

Abstract

We demonstrated for the first time that Na-intercalated H(2)Ti(3)O(7) (Na(x)H(2-x)Ti(3)O(7)) NBs, prepared in the typical alkaline hydrothermal process, can effectively absorb visible light to carry out photocatalytic reactions. With the capability of effective light absorption in visible range, Na(x)H(2-x)Ti(3)O(7) NBs performed much better in the photoclegradation of thionine than the other three counterpart products including H(2)Ti(3)O(7), mixed Na(2)Ti(6)O(13)/TiO(2) and anatase TiO(2) under visible-light irradiations. As compared to the relevant commercial products like P-25 TiO(2) and Na(2)Ti(3)O(7) powders, the as-synthesized Na(x)H(2-x)Ti(3)O(7) NBs exhibited superior photocatalytic efficiency under UV illumination, demonstrating their potential as an efficient photocatalyst in relevant redox reactions. A further enhancement in the photocatalytic activity can be achieved for Na(x)H(2-x)Ti(3)O(7) NBs when Au nanoparticles of suitable amount were deposited on their surfaces. This improvement is due to the band offsets between Na(x)H(2-x)Ti(3)O(7) and Au, which may promote charge carrier separation to favor the photocatalysis. The recycling test reveals that Au-decorated Na(x)H(2-x)Ti(3)O(7) NBs could be promisingly utilized in the long-term course of photocatalysis. Furthermore, the result of performance evaluation under natural sunlight shows that the current Au-decorated Na(x)H(2-x)Ti(3)O(7) NBs can be used as highly efficient photocatalysts which may practically harvest energy from sunlight. (C) 2010 Elsevier B.V. All rights reserved.