Capped Keggin Type Polyoxometalate-Based Inorganic–Organic Hybrids Involving In Situ Ligand Transformation as Supercapacitors and Efficient Electrochemical Sensors for Detecting Cr(VI)

作者：Xiang Wang, Huan Li, Jia-Feng Lin, Chenying Wang, Xiuli Wang · 发表于：Inorganic Chemistry · 年份：2021 · DOI：10.1021/acs.inorgchem.1c03097 · 被引用次数：50 · 研究领域：Polyoxometalates: Synthesis and Applications、Metal-Organic Frameworks: Synthesis and Applications、Advanced Nanomaterials in Catalysis

To construct polyoxometalate-based complexes as electrode materials for supercapacitors and electrochemical sensors, we intentionally used in situ ligand transformation during the reaction. Two complexes based on polyoxometalates capped by zinc ions, H{Zn 4 (DIBA) 4 [(DIBA)(HPO 2 )] 2 (α-PMo VI 8 Mo V 4 O 40 Zn 2 )} ( 1 ) and [ε-PMo V 8 Mo VI 4 O 37 (OH) 3 Zn 4 (HDBIBA) 2 ]·6H 2 O ( 2 ) [DIBA = 3,5-di(1 H -imidazol-1-yl)benzoic acid, and DBIBA = 3,5-bis(1 H -benzoimidazol-1-yl)benzoic acid], have been prepared successfully. The DIBA and DBIBA ligands were generated in situ from initial materials 3,5-di(1 H -imidazol-1-yl)benzonitrile and 3,5-di(1 H -benzoimidazol-1-yl)benzonitrile. The three-dimensional structure of 1 consisted of two-dimensional interpenetrating layers and polyoxometalate-based chains composed of bicapped α-PMo 12 Zn 2 polyoxoanions and phosphite-modified DIBA ligands. In 2, a kind of tetracapped ε-PMo 12 Zn 4 polyoxoanion exists, which was further linked by DBIBA ligands into a one-dimensional chain. Two complexes could be employed as not only electrode materials for supercapacitors with specific capacitances of 171.17 F g –1 for 1 and 146.77 F g –1 for 2 at 0.5 A g –1 but also efficient electrochemical sensors for detecting Cr(VI) with excellent limits of detection of 0.026 μM for 1 and 0.035 μM for 2, which represents a hopeful approach for exploiting polyoxometalate-based complexes as supercapacitor and electrochemical sensor materials.