离子液体型多金属氧酸盐[PyPS]nH3-nPW12O40·xH2O的合成及其对水溶液中染料的光催化脱色作用

以吡啶、丙磺酸内酯和钨磷酸为原料，合成了离子液体型多金属氧酸盐（POM-IL）化合物PyPS]nH3-nPW12O40·xH2O（n=1，2，3），用FT-IR、UV-Vis、1H NMR和元素分析等对其进行了表征。 结果显示，POM-IL化合物仍保持相应钨磷酸的Keggin结构，并存在吡啶丙磺酸的特征谱带，熔点均高于130 ℃，且随有机阳离子含量增加，熔点降低。 在紫外光下，n为1和2的POM-IL对水溶液中甲基橙的光催化降解活性与钨磷酸相似；在可见光下，POM-IL对水溶液中靛红的光催化降解活性相近，且均远高于钨磷酸。

Preparation of Ionic Liquid-like Polyoxometalates [PyPS]nH3-nPW12O40·xH2O and Their Photocatalytic Performances to Decoloration of Dyes in Aqueous Solution

Ionic liquid-like polyoxometalates(POM-IL), PyPS]nH3-nPW12O40·xH2O(n=1,2,3), were synthesized by using pyridine, 1,3-propanesultone and tungstophosphoric acid as raw materials. The compounds were characterized by means of FT-IR, UV-Vis, 1H NMR and elementary analyses. The results showed that Keggin structure of POM was kept and there were character bands of pyridyl propylsulfonic acid in the POM-IL salts. All prepared compounds possess melting-points above 130 ℃ and the melting-points decreased with the increase of the organic component. Furthermore, the photocatalytic performances of these POM-IL samples for the degradation of aqueous dyes were investigated. Under UV irradiation, the samples with n=1 and 2 showed similar photocatalytic activities to that of tungstophosphoric acid for the degradation of methyl orange. Under visible light, all POM-IL salts exhibit the same photocatlytic activities which are superior to tungstophosphoric acid for the degradation of isatin. Therefore, all these POM-IL salts might be promising photocatalysts for the degradation of some dyes under visible light.