A new approach to the preparation of microcrystalline ZnNb_2O_6 photocatalysts via a water-soluble niobium-citrate-peroxo compound

摘要

A water-soluble niobium-citrate-peroxo compound was synthesized by using Nb_2O_5 as a precursor. This niobium compound solution was successfully applied to the preparation of microcrystalline ZnNb_2O_6 photocatalysts via a water-based sol-gel method. The results indicated that pure ZnNb_2O_6 could be ob?tained in a temperature range from 750 to 950 °C. The absorption edge of ZnNb_2O_66 located at about 305 nm, corresponding to a band gap of ca. 4.06 eV. The photocatalytic activities of the as-prepared samples for the methyl orange degradation were evaluated under UV light (A = 254 nm). It was found that the sample obtained at 850 °C showed the highest photocatalytic activity due to its suitable surface area and crystallinity.