Hydrothermal synthesis and photocatalytic property of KNb3O8 with nanometer leaf-like network

The KNb3O8 photocatalyst with nanometer leaf-like network was obtained by the hydrothermal synthesis. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to characterize the morphologies and structure of the photocatalyst. The band gap of KNb3O8 crystals was estimated to be about 3.47 eV from the onset of UV–vis diffuse reflectance spectrum of the photocatalyst. The crystalline of KNb3O8 catalyst prepared becomes well with increasing the hydrothermal reaction time, which markedly increases the photocatalytic activity of the catalyst. The photocatalytic degradation reaction of acid red G on the catalyst KNb3O8 is a pseudo-first-order reaction. Although the surface areas of the photocatalyst prepared are much lower than that of P25-TiO2, its photocatalytic activity of photodegrading acid red G is much higher than that of P25-TiO2.