The design and synthesis of a bifunctional catalyst to tackle environmental pollution caused by 2-chloroethyl ethyl sulfide (CEES) and phenolic compounds is meaningful. In this study, a new three-dimensional (3D) polyoxovanadate (POV)-based metal–organic framework, [Co(L)(V₄O₁₂)_0.5(H₂O)]·2H₂O (1; L = N,N’-bis(3-methylpyridin-3-yl)-2,6-naphthalenediamide), was synthesized under hydrothermal conditions. 1 was characterized using single-crystal X-ray diffraction analysis, infrared spectroscopy, and powder X-ray diffraction. Structural analysis shows that the [V₄O₁₂]^4– clusters and pairs of Co²⁺ cations are alternately connected to form a one-dimensional inorganic chain, eventually generating a 3D (4,4)-connected framework through the expansion of L, which exhibits a two fold interpenetration array. As a bifunctional catalyst, 1 exhibits satisfactory catalytic properties for the selective oxidation of 2-chloroethyl ethyl sulfide to the corresponding sulfoxide, with an effective conversion of > 99% and selectivity of 97%. Furthermore, 1 exhibits excellent photocatalytic degradation activity toward phenol, 2-chlorophenol, and m-cresol under visible light. The degradation efficiencies were above 92.6% for 140 min. The photocatalytic reaction kinetics, mechanisms of photodegradation, and recycling capability of phenol were also investigated in detail.

Under hydrothermal conditions, a Keggin-type polyoxometalate-based metal–organic complex, H₄{[Cu₄(EDDP)₂(H₂O)₅]_1.5(SiW₁₂O₄₀)}∙7.5H₂O (CuW-EDDP, H₄EDDP = ethylene-diamine-N,N'-dipropionic acid), was synthesized by reacting Na₁₀[A-α-SiW₉O₃₄]·18H₂O and CuCl₂·2H₂O in the presence of H₄EDDP ligands and characterized by powder and single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, and thermogravimetry. Interestingly, CuW-EDDP exhibited a three-dimensional structure with (4,6)-connected constructed from [SiW₁₂O₄₀]⁴⁻ units and tetranuclear Cu complexes [Cu₄(EDDP)₂(H₂O)₅]. As an effective heterogeneous catalyst, CuW-EDDP exhibited excellent performance, good reusability, and structural stability in the selective oxidation of methyl phenyl sulfide with high conversion (100%) and selectivity (98%) within 30 min. Furthermore, the catalytic activity of CuW-EDDP in the oxidation of other sulfide derivatives was investigated.