Water assisted high proton conductance in a pure-inorganic framework vanadoborate†
Abstract
A new pure-inorganic framework vanadoborate H10[V12B18O54(OH)6]·20H2O (1) was hydrothermally synthesized and structurally characterized. Its inorganic framework was constructed by discrete [V12B18O54(OH)6]10− polyanion clusters decorated with H+ as a counterion. For 1, the abundant water molecules in its one-dimensional (1D) channels, together with pure H+ and –OH groups from its framework, cooperate to create a continuous hydrogen bond network. Pure H+ and extensive H-bonds in the framework facilitate fast proton conduction, and endow this compound with a good proton conductivity of 2.36 × 10−3 S cm−1 at 353 K and 100% RH, which is ultra-high for vanadoborate-based proton-conducting materials and also can compete with those of numerous state-of-the-art MOF-based proton conductors.