Post-synthesis functionalization of ZIF-90 with sulfonate groups for high proton conduction

Abstract

Introducing sulfonic acid groups into MOF materials is one of the effective approaches to enhance proton conduction. Here, we attempted to prepare a new post-modified ZIF-90-based material by addition reaction of the aldehyde group with bisulfite to obtain partially functionalized ZIF-90-SO₃Na_(2.3). ZIF-90-SO₃Na_(2.3) exhibits a high proton conductivity of 2.26 × 10⁻² S cm⁻¹ at 98% RH and 100 °C.