Synthesis, Crystal Structures, and Thermal Analyses of Two New Antimony Tellurite Sulfates: [Sb2(TeO4)](SO4) and [Sb2(TeO3)2](SO4)

Abstract

AbstractTwo new antimony (III) tellurite sulfates [Sb2(TeO4)](SO4) (1) and [Sb2(TeO3)2](SO4) (2) were successfully synthesized through a conventional hydrothermal method and their crystal structures were determined by X‐ray single crystal analysis. [Sb2(TeO4)](SO4) crystallizes in the triclinic space group Pī (No. 2) with lattice parameters a=5.572(2), b=7.247(2), c=9.540(3) Å, V=358.5(2) Å3, and Z=2, while [Sb2(TeO3)2](SO4) crystallizes in the orthorhombic space group Pbca (No. 61) with lattice parameters a=7.368(2), b=14.571(3), c=16.521(3) Å, V=1773.7(6) Å3, and Z=8. The structure of [Sb2(TeO4)](SO4) features a three‐dimensional framework, composed of [SbO4] trigonal bipyramids and [TeO4] polyhedra to form a cationic 2∞[Sb2(TeO4)]2+ corrugated cationic layers along [100], linked by SO42− anions. [Sb2(TeO3)2](SO4) forms a three‐dimensional framework consisting of two dimensional wrinkled layers of 2∞[Sb2(TeO3)2]2+ that are linked by SO42− anions. The band gaps of 4.16 eV and 3.72 eV for [Sb2(TeO4)](SO4) and [Sb2(TeO3)2](SO4) respectively are estimated from the solid state UV‐vis‐NIR diffuse reflectance spectra. Thermal analysis indicated that both compounds are thermally stable up to about 500 °C. The electrochemical specific capacity of [Sb2(TeO4)](SO4) was determined to 245 mA h g−1 on the first cycle in a Li‐ion half‐cell, the capacity remains at about 106 mA h g−1 after 500 cycles.