基于Keggin型杂多酸的无机-有机杂化物的合成和光催化活性

采用水热合成方法制备了2个基于Keggin型杂多酸的无机-有机杂化物, 化学式分别为{Cu₂(4,4′- bipy)₄(H₂O)₄](SiMo₁₂O₄₀)·18H₂O}_n(1)和{Cu₂(4,4′-bipy)₄(H₂O)₄](PMo₆W₆O₄₀)·18H₂O}_n(2)(bipy=bipyridine). 结构分析 表明2个化合物同构, Cu²⁺是六配位, 分别与4个4,4′-bipy上的N原子和2个水分子上的O原子结合, 形成 Cu(4,4′-bipy)₂(H₂O)₂]_n²ⁿ⁺二维层状结构. 杂多阴离子通过静电与配位阳离子Cu(4,4′-bipy)₂(H₂O)₂]_n²ⁿ⁺作用交叉排列在层间. 通过红外光谱、 粉末X射线衍射和固体紫外-可见漫反射光谱等对化合物的性质进行了表征. 研究了所合成化合物对水溶性染料亚甲基蓝的降解活性, 发现2种化合物对于亚甲基蓝均表现出显著的光降解活性, 并对它们的催化机理进行了讨论.

Synthesis and Photocatalytic Degradation Activity of Two Inorganic-organic Hybrids Based on Keggin-type Heteropolyacids

Two inorganic-organic hybrids based on Keggin-type heteropolyacids with the chemical formula ｛［Cu₂（4，4′-bipy）₄（H₂O）₄］（SiMo₁₂O₄₀）·18H₂O｝_n（1） and ｛［Cu₂（4，4′-bipy）₄（H₂O）₄］（PMo₆W₆O₄₀）·18H₂O ｝_n（2）（bipy=bipyridine） were prepared. The single crystal X-ray analysis shows that the two compounds are isostructural， in which the Cu²⁺ is six-coordinated， ligated by four N atoms from four 4，4′-bipy and two O atoms from the two water molecules， forming a 2D cation layer ［Cu（4，4′-bipy）₂（H₂O）₂］_n²ⁿ⁺. Keggin-type heteropolyanions are arranged between the 2D cation layers by electrostatic interaction with coordination cations ［Cu（4，4′-bipy）₂（H₂O）₂］_n²ⁿ⁺. These compounds are characterized by infrared spectroscopy， powder X-ray diffraction and solid ultraviolet-visible diffuse reflectance spectroscopy. The degradation activity of synthetic compounds on the water-soluble dye methylene blue was researched. The experimental results indicate that the two compounds exhibit significant photodegradation activity for methylene blue， and the catalytic mechanism is discussed.