Unique protonconduction 3D Zn-II metal organic framework exposure to aquaammonia vapor to enhance conductivity

Recently, metal-organic frameworks (MOFs) have been receiving increasing attention because their modular budding blocks give them diversity and functional adjustability. MOFs have achieved excellent results as novel proton-conducting materials. However, there are relatively Limited studies on the properties of proton-conducting MOFs that can be regulated by changing the test environment. Herein we explored the proton conductivity of a Zn-II MOF {[Zn-3(m-MOD)(2)(H2O)(6)]center dot 4H(2)O}(n) (ZS-1) (m-MOD = 2-(3-methoxy phenyl)-1H-imidazoLe-4,5-dicarboxyLicacid) at humidity and aquaammonia vapor. ZS-1 has a 3D structure in the shape of a windmill, which contains hexagonal one-dimensional channels and a Large number of free and coordination water molecules, providing convenient conditions for proton conduction. ZS-1 obtained an optimal conductivity of 1.38 x 10(-3) S cm(-1) (100 degrees C) under 2 M aquaammonia vapor, which was about three orders of magnitude higher than the maximum conductivity under water vapor (5.31 x 10(-6) S cm(-1), 100 degrees C-98% RH). The proton conduction mechanism is discussed in depth by combining the structural characteristics and related characterizations.