Synthesis, Characterization, and Application of a Polyoxometalates‐Based CuII Complex for Efficient Catalytic Oxidation and Electrochemical Detection

Abstract The development of eco‐friendly, high‐efficiency polyoxometalates (POMs) catalysts is vital for advancing catalytic oxidation and electrochemical detection in environmental protection. Herein, a POM‐based Cu II ‐containing complex with the molecular formula [H(4‐AP)] 8 [Cu 2 (H 2 O) 4 (P 2 Mo 5 O 23 ) 2 ]·8H 2 O ( 1 ) (4‐AP = 4‐aminopyridine) is synthesized using the hydrothermal method, and the crystal structure is determined by single X‐ray diffraction (SXRD), infrared (IR) spectroscopy, and powder X‐ray diffraction (PXRD). Structurally, complex 1 exhibits a one dimension (1D) chain arrangement, composed of Cu II ions and Strandberg‐type (P 2 Mo 5 O 23 ) 6− anionic clusters. These 1D chains are further interconnected through [H(4‐AP)] + ligands, resulting in the formation of a two dimension (2D) supramolecular network. Complex 1 serves as an outstanding heterogeneous catalyst for the oxidation of methyl phenyl sulfide (MPS), demonstrating a remarkable conversion rate of 99% for MPS and a selectivity of 98% toward methyl phenyl sulfoxide (MPSO). In addition to its catalytic capabilities, complex 1 is also employed in the electrochemical detection of Fe III and Cr VI ions, with low limits of detection (LODs) at 4.92 µ m for Fe III and 7.82 µ M for Cr VI .