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

Abstract

Cu-doped KNb 3O 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 6Nb 10.8O 30 with tungsten–bronze structure and the relative content of K 6Nb 10.8O 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 6Nb 10.8O 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 3O 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.