High-efficiency photo- and electro-catalytic material based on a basket-like {Sr⊂P6Mo18O73} cage

Abstract

A novel high-efficiency photo-/electro-catalyst based on phosphomolybdate (H₄bth)[{Mn₂(H₂O)₃} {Sr⊂P₆Mo₂^VMo₁₆^VIO₇₃}]·3H₂O (1) (bth = 1,6-bis(triazole)hexane), has been hydrothermally synthesized and characterized by X-ray crystallographic analyses, FT-IR, UV-vis, TG-DTA, XRD, XPS, and the elemental analyses. Compound 1 is an eight-connected 2-D layer structure, which represents the highest-connected assembly of basket-type POMs. The compound exhibits universal high-efficient degradation ability for the azo dyes MB, RhB, and AP under UV and visible light irradiation. The catalyst has a long lifetime and can be recovered and reused with a slight loss of reactivity. The major photoreaction pathways of three dyes on the surface of catalyst 1 were detected by a series of radical trapping experiments. The result suggests that ˙O₂⁻, ˙OH radicals and photogenerated h⁺ play different roles in the degradation process. The diffuse reflectivity spectrum provides essential evidences for the highly-efficient oxidation performance of basket-liked POMs. The compound also shows good bifunctional electrocatalytic behavior for oxidation of AA and reduction of NO₂⁻.