Dimeric four tartaric acid‐bridged tetra‐Zr‐incorporated arsenotungstate showing decent proton conduction
Dong‐Sheng Yang, Lihua Liu, Jiayu Liu, Zi-Yao Fu, Tianjiao Li, Xiang Ma, Lin Sun, Pengtao Ma
Abstract
Exploring a new and robust material for proton conduction is of significant importance to the scientific interest and technological importance. Polyoxometalates (POMs) are a class of molecular anion metal oxide clusters with well‐defined structures and diverse properties. Therefore, the design and synthesis of a POM‐based material for proton conduction is extremely vital. Herein, a dimeric four tartaric acid‐bridged tetra‐Zr‐incorporated arsenotungstate, [NH 2 (CH 3 ) 2 ] 16 KH 7 [{Zr(tarH) O 2 } 4 {As 2 W 19 O 68 } 2 ]·16H 2 O ( 1 ) (tarH = tartaric acid), was successfully synthesized via a conventional aqueous method that utilized the tartaric acid ligand protection strategy, and it was systematically characterized by powder X‐ray diffraction (PXRD), thermo gravimetric analysis (TGA), infrared (IR), ultraviolet (UV) spectra and energy‐dispersive X‐ray spectroscopy (EDS). This strategy included an innovative [Zr(tarH)WO 2 ] 4 8+ core sandwiched by two distorted [As 2 W 19 O 68 ] 16− subunits. The [Zr(tarH)WO 2 ] 4 8+ core is constituted of four Zr 4+ and four {WO 2 } groups, which are linked together by four tartaric acid ligands. Interestingly, the four tartaric acid ligands decorated on Zr 4+ are covalently modified toward the W atoms. Moreover, the impedance measurements demonstrate that 1 has excellent proton conduction properties with the proton conductivity value of 3.82 × 10 −3 S·cm −1 under 348 K and 95% RH.