Hexahydric component metal organic frameworks constructed by multiple ligands and mixed-valence ions

Abstract

In this work, we report two multi-component MOFs [CH₃NH₂CH₃]₂[Fe^III₂M^II₁₀(tz)₁₁(HCO₂)₁₂(btc)_5/3] (M^II₁₀ = Fe^II₁₀ for 1 and M^II₁₀ = Fe^II₂Co^II₈ for 2) obtained by solvothermal reaction of benzene-1,3,5-tricarboxylate (btc) and 1,2,4 triazole (tz), Fe^II and Fe^III/Co^II in DMF. In the complexes, several different types of metal rings (9, 12-number metal ions) are generated, and the connection of those rings gives the complicated three-dimensional structure. The two complexes exhibit electronic conductivity and good alkali stability, which makes them potential OER electrocatalysts. It is revealed that the cobalt ion greatly enhances the OER performance, and the electrode prepared using 2 shows a low overpotential of 339 mV at 10 mA cm⁻¹.