Layered niobate KNb^sub 3^O^sub 8^ synthesized by the polymeric precursor method

The polymeric precursor method was used for the synthesis of KNb3O8 and compared to the solid-state method. The materials were characterized by X-ray diffraction (XRD), infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and determination of surface area and total pore volume by nitrogen isotherms at 77 K. The material prepared by the polymeric precursor method was single-phase while K2Nb4O11 was obtained as secondary phase when the solidstate method was used, as evidenced by the XRD patterns and the Raman spectra. The morphology of the materials was significantly altered by the synthesis method, as the KNb3O8 prepared by the polymeric precursor method presented a more porous morphology leading to a higher surface area and pore volume.