摘要
A lacunary Keggin-type tungstosilicate dimer-estertin derivative,(C(NH_(2))_(3))_(7)H_(3.5)[(K⊂Ni H_(2)O)_(2)(SnCH_(2)CH_(2)COO)((Ni(H_(2)O))_(0.75)(WO)_(0.25))(Si_(2)W_(18)O_(67))]·6H_(2)O(abbreviated as Si_(2)W_(18)-Ni-SnRCOO,R=CH_(2)CH_(2)),was synthesized by using the conventional aqueous solution method,and characterized by a series of physical and spectral methods.Single crystal X-ray structural analysis revealed that the polyoxometalate(POM)was a dimeric tungstosilicate-based organic-inorganic hybrid compound,which contained two Ni ions and a cyclic carboxyltin group(SnRCOO).Unexpectedly,the carboxyl-oxygen atom of SnRCOO acted as a bridging oxygen atom belonged to the POM skeleton and connected to NiO_(6)octahedron.The thermal and photocatalytic activities of Si_(2)W_(18)-Ni-SnRCOO were studied.As a homogeneous catalyst,the conversion of cyclohexanol to cyclohexanone was as high as 98%,and the degradation efficiency of 20 mg·L^(-1)RhB reached 88%.The experimental results showed that the introduction of the carboxyethyltin group significantly enhanced the catalytic activity of this type of POM-based catalyst.Additionally,the composite of Si_(2)W_(18)-Ni-SnRCOO and TiO_(2) enabled the catalyst to be recycled,and the photocatalytic efficiency of Si_(2)W_(18)-Ni-SnRCOO/TiO_(2) remained almost unchanged after five cycles.
采用常规水溶液法合成了一种缺位Keggin型钨硅酸盐二聚体酯锡衍生物(C(NH_(2))_(3))_(7)H_(3.5)[K⊂Ni(H_(2)O)_(2)(SnCH_(2)CH_(2)COO)((Ni(H_(2)O))_(0.75)(WO)_(0.25))(Si_(2)W_(18)O_(67))]·6H_(2)O(简写为Si_(2)W_(18)-Ni-SnRCOO,R=CH_(2)CH_(2)),并通过一系列物理和光谱方法进行了表征。单晶X射线结构分析表明,这种多金属氧酸盐(POM)是一种二聚钨硅酸盐基有机-无机杂化化合物,含有Ni离子和环状羧基锡(SnRCOO)基团。出乎意料的是,SnRCOO的羧基O原子充当了POM骨架与NiO_(6)八面体之间的桥O原子。并研究了Si_(2)W_(18)-Ni-SnRCOO的热催化活性和光催化活性,作为均相催化剂,其催化环己醇氧化为环己酮的转化率高达98%;对20mg·L^(-1)罗丹明B(RhB)的降解效率达到88%。实验结果表明,引入羧乙基锡基团显著提高了这种POM基催化剂的催化活性。此外,Si_(2)W_(18)-Ni-SnRCOO与TiO_(2)复合使催化剂能够回收利用,其光催化效率在五次循环后几乎保持不变。
出处
《分子科学学报》
2024年第5期462-470,共9页
Journal of Molecular Science
基金
financially supported by the National Natural Science Foundation of China (21671091 and 21503103)
the Startup Project of Doctor Scientific Research from Liaoning Normal University (2023BSL017)
