Keggin型钨硅酸-镍-联咪唑的合成及电催化性能

Synthesis and electrocatalytic performance of Keggin-type Ni-Hbiim-tungstosilicates

依据自组装原理,分别采用常规水溶液和水热合成方法,以缺位程度不同的钨硅酸盐为前驱体,合成了2例含有饱和Keggin结构阴离子[SiW12O40]^4-和Ni(Ⅱ)-H2biim/H2O(H2biim=2,2′-联咪唑)配阳离子的无机-有机杂化化合物[Ni(H2biim)2(H2O)2]2[SiW12O40]·5H2O(化合物1)和[Ni(H2biim)2(H2O)2]2[SiW12O40]·6H2O·2CH3COOH(化合物2),并通过X射线单晶衍射(SCXRD)、元素分析、红外光谱(IR)、粉末X射线衍射(PXRD)及热重(TG)分析对2例化合物进行了表征.SCXRD结果分析表明,2例化合物具有相同的阴离子结构,其结晶水个数和配阳离子中2个H2biim配体间形成的夹角不同,且化合物2的外围有CH3COOH分子存在.研究了2例化合物在水溶液中的电化学性质及其电催化还原H2O2和NaNO2的性能.

According to the self-assembly principle,two inorganic-organic hybrid compounds containing saturated Keggin-type polyoxoanion[SiW12O40]^4- and Ni-H2biim/H2O(H2biim=2,2′-biimidazole)complex cation,i.e.[Ni(H2biim)2(H2O)2]2[SiW12O40]·5 H2O(compound 1)and[Ni(H2biim)2(H2O)2]2[SiW12O40]·12H2O(compound 2),were synthesized by conventional and hydrothermal method from different tungstosilicate precursors with different degrees of vacancies,respectively.Compounds 1 and 2 were characterized by single-crystal X-ray diffraction(SCXRD),elemental analysis,infrared spectroscopy(IR),powder X-ray diffraction(PXRD)and thermogravimetric(TG)analysis.The SCXRD analysis showed that the two compounds exhibit the same anionic structures,but the number of crystal water molecules and the angles between the two H2biim molecules in the complex cations were different,and there are two CH3COOH molecules in compound 2.At the same time,the electrochemical property of the two compounds in aqueous solution and their electrocatalytic activity for the reduction of H2O2 and NaNO2 were studied.