Synthesis And Properties Of Layered Niobate Series Nanocompsite Photocatalyst

Layered photocatalytic nanocomposite is a new type of photocatalytic material. Incorporation of semiconductor particles via chemical reactions in the interlayer region of a lamellar compound is a promising method for the fabrication of a nanocomposite consisting of host layers with ultrafine particles highly dispersing in the interlayer, having greater specific surface areas. These nanocomposites not only have photocatalytic activities of semi-conductor and layered compound, but also have actual meaning in resolving problems of semi-conductor carrying into layered compound.A series of layered niobate were synthesized by calcining the mixture of stoichiometric start materials. For example, KLaNb₂O₇, KNdNb₂O₇, KCeNb₃O₁₀, KFeNb₂O₇, KNi₂Nb₃O₁₀. And then HLaNb₂O₇ / n-C₃H₇NH₂, HLaNb₂O₇ / n-C₄H₉NH₂, HLaNb₂O₇ / n-C₆H₁₃NH₂, HLaNb₂O₇/ n-C₉H₁₉NH₂ were prepared by using refluxing synthesis method; HNdNb₂O₇/ TiO₂, HNdNb₂O₇/ (TiO₂, Pt) , HNdNb₂O₇/ Pt, HNdNb₂O₇/ Fe₂O₃, HNdNb₂O₇/(Pt, Fe₂O₃) nanocomposites with ultrafine particles highly dispersing in the interlayer were prepared by using sol-gel or hydrothermal synthesis method. These samples were characterized by TG-DTA. XRD, DRS, Specific surface area analysis and Atomic absorption spectrometry analysis. The photocatalytic activities of the samples were evaluated by measuring the volume of hydrogen gas evolved when the suspensions of the samples was irradiated with ultraviolet light using methyl alcohol as cavity sacrifice agent.The results show that photocatalytic activities of the layered nanocomposites are superior to those of unsupported TiO₂, Fe₂O₃ and Pt. Furthermore, the photocatalytic experiment also indicate that HNdNb₂O₇/TiO₂, HNdNb₂O₇/Pt, HNdNb₂O₇/ Fe₂O₃, HNdNb₂O₇/ (TiO₂, Pt),...