The induced synthesis of mixed phase niobate by Cu doping and its photocatalytic property

Cu-doped KNb(3)O(8) photocatalysts were prepared using a simple solid-state method. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectrum. XRD and SEM analyses suggest that Cu doping can induce the formation of the compound K(6)Nb(10.8)O(30) with tungsten-bronze structure and the relative content of K(6)Nb(10.8)O(30) in the Cu-doped samples increased with increasing Cu doping amount. When the Cu doping amount reaches 2 wt.%, the as-prepared sample is mainly composed of K(6)Nb(10.8)O(30). The photocatalytic properties of the catalysts were evaluated using the degradation of acid red G. The results showed that Cu-doping significantly increased the photocatalytic activity of the KNb(3)O(8) catalyst. The optimum dopant concentration range of Cu was found to be 0.3-1 wt.%. The synergistic effect of Cu doping and mixed phase niobate compounds is responsible for the enhanced photocatalytic activity. (C) 2011 Elsevier B.V. All rights reserved.