A New [PMoO]-Based Ni Compound: Electrochemical and Photocatalytic Properties for Water Pollutant Removal.

A polyoxometalate-based metal-organic complex with the ability to treat pollutants in water was obtained under hydrothermal conditions, namely Ni(HL)(HL)·3HO·4HO () (HL = 4,4'-(1H,1'H-[2,2'-biimidazole]-1,1'-diyl)dibenzoicacid). Structural analysis reveals that the [Ni(HL)(HL)] units are interconnected into a 2D layer via hydrogen bonds between adjacent carboxyl groups and water molecules of crystallization. [PMoO] anions are embedded within the larger pores of the layer and are connected to the adjacent layers through hydrogen bonds, ultimately expanding the structure into a 3D supramolecular architecture. The intermolecular interactions were studied via Hirshfeld surface (HS) analysis. Electrochemical performance tests reveal that exhibits electrocatalytic activity toward the oxidation and reduction of diverse pollutants in water, including NO, Cr(VI), BrO, Fe(III), and ascorbic acid (AA). Additionally, it can also serve as an amperometric sensor for the detection of BrO and Cr(VI). Photocatalytic studies reveal that compound functions as a bifunctional photocatalyst, which not only achieves efficient degradation of organic dyes but also demonstrates remarkable reduction efficiency for toxic Cr(VI). Compound demonstrates significant potential for practical water remediation applications.