Three‐dimensional TiO ₂ /Bi ₂ WO ₆ hierarchical heterostructure with enhanced visible photocatalytic activity

Abstract

A three‐dimensional TiO 2 /Bi 2 WO 6 hierarchical heterostructure was successfully prepared by a simple and practical liquid phase method. The as‐synthesised nanostructure consisted of TiO 2 nanoparticles growing on the surface of flower‐like Bi 2 WO 6 microspheres. The UV–vis diffuse reflectance spectra indicated that the TiO 2 /Bi 2 WO 6 composites have a significantly enhanced optical absorption in the visible light region and red‐shift phenomenon compared with that of pure Bi 2 WO 6 microspheres. The photocatalytic activity of the TiO 2 /Bi 2 WO 6 composites increases first and then decreases with increasing loading content of TiO 2 under 500 W Xe lamp light irradiation. The composite coated with 3 ml content tetrabutyl titanate showed the highest photocatalytic activity compared with that of the other samples in the decomposition of Rhodamine B in water which is a typical model pollutant. The improved light harvesting ability and efficient separation of photo‐generated electron and hole pairs could be responsible for the improved photocatalytic performance.