An acid-base resistant polyoxometalate-based metal–organic framework constructed from {Cu4Cl}7+ and {Cu2(CO2)4} clusters for photocatalytic degradation of organic dye

Abstract

The construction of acid-base resistant materials for elimination of organic contaminations in water under the sunlight conditions is very important for the protection of our living surroundings. Metal-organic frameworks (MOFs) are promising candidates for photocatalytic applications, but many of them suffer from poor framework stability under the acidic or basic conditions. In this study, by using a bifunctional ligand 4-(4-carboxyphenyl)-1,2,4-triazole (HCPT) featuring both carboxylate and azole groups, a new polyoxometalate-based MOF formulated as {[Cu8Cl5(CPT)8(H2O)4](HSiW12) (H2O)20(CH3CN)4}n (1) has been prepared via a solvothermal approach. Complex 1 shows a 3D 2-fold interpenetrating scu-type network based on the four-connected {Cu2(CO2)4} and eight-connected {Cu4Cl}7+ clusters, and could be stable in a wide range of pH values f0 to 14). Apart from its excellent framework stability, complex 1 shows a high photocatalytic efficiency for the degradation of rhodamine B (RhB) by visible light irradiation and nearly 97% of the RhB was degraded within 70 ​min. To our knowledge, complex 1 represents the first case of polyoxometalate-based MOFs constructed from the mixed-cluster units.