3D organic-inorganic hybrid based on Strandberg-type cluster of [(PIIIO3)2Mo5O15]6-: Synthesis, crystal structure and electrochemical properties

The rational design of crystalline materials coupled with polyoxometalate as electrocatalyst is an effective strategy for the sensitive electrochemical detection of H2O2. Here, a new organic-inorganic hybrid, H-2(NH4)(3)[Him][((PO3)-O-III)(2)Mo5O15]center dot 4H(2)O (1) (im=imidazole), was isolated by a one-pot self-assembly strategy. Structural analysis indicates that compound 1 adopts a three-dimensional (3D) supramolecular structure based on the Strandberg-type [((PO3)-O-III)(2)Mo5O15](6-) clusters linked with protonated [Him](+) cations via hydrogen bond interactions. Electrochemical studies reveal that compound 1 exhibits the multi-electron redox processes ascribed to Mo-VI centers, and has good electrocatalytic activity in the reduction of H2O2. By utilizing compound 1 as electrode material, the designed electrode showed excellent electrochemical performance towards H2O2 detection, including a wide linear range (50-450 mu M), high sensitivity of 0.085 mu A.mu M-1 and a low detection limit of 3.52 mu M, as well as good selectivity and stability.