Abstract:  Gd doped nano-flake K4Nb6O17 photocatalysts with high crystallinity were prepared by using KOH，Nb2O5，and Gd（NO3）3 as raw materials under hydrothermal conditions.The morphology and structure of the prepared photo-catalysts were characterized by XRD，SEM，TEM，snd XPS etc..The degradation performance to rhodamine was also investigated.Results showed that the doping of Gd increased the crystallinity of K4Nb6O17.The catalyst with a doping content of Gd of 0.5%（amount-of-substance fraction） had the best performance for rhodamine degradation.Under the radiation of ultraviolet lamp，30 mg of catalyst could effectively degraded 100 mL of rhodamine with a mass concentration of 20 mg/L.

Key words: potassium niobate, hydrothermal synthesis, photocatalysis