Crown-type tetranuclear Ag-POM exhibits excellent proton conductivity performance

Abstract

A crown-type tetranuclear Ag-POM, Na₂₄[Ag_3.4Na_0.6(As₄W₄₀O₁₄₀)]·82H₂O (1), was synthesized based on the structural features of {As₄W₄₀} using simple materials through the hydrothermal method. The polyanion of compound 1 consists of a tetranuclear silver cluster embedded in the cyclic ligand {As₄W₄₀} and the polyanions linked by Na⁺ to form a 3D framework. Moreover, compound 1 exhibits excellent proton conductivity, with an optimal conductivity of 2.24 × 10⁻² S cm⁻¹ at 90% RH, 358 K. Furthermore, it demonstrates outstanding cycling stability during heating–cooling cycles and durability over 68 h.