Synthesis and crystal structure of a novel layered barium antimonate Ba2Sb7O13(OH) with mixed-valence antimony

•A novel barium antimonite with mixed-valence Sb3+ and Sb5+ cations, Ba2Sb7O13(OH), was hydrothermally synthesized.•The crystal was characterized structurally and optically.•Electronic band structure and density of states (DOS) were studied.

The compound of Ba2Sb7O13(OH) was synthesized by using hydrothermal method from starting reagents of Ba(OH)2·8H2O, Sb2O3 and KCl. The crystal structure of Ba2Sb7O13(OH) was determined and characterized by single crystal X-ray diffraction method. Ba2Sb7O13(OH) represents a novel two-dimensional layered structure which is composed of SbVO6 and SbIIIO4 polyhedra through sharing corner oxygen atoms. Two types of Sb cations with Sb3+ in sphenoid SbO4 polyhedra and Sb5+ in octahedral SbO6 fashion are mixed in the crystal structure. First-principles electronic structure calculations based on the density functional theory (DFT), as well as the optical diffuse reflectance spectroscopy measurements, indicate that the compound belongs to an indirect band semiconductor with optical band gap of 2.7 eV.

Graphical abstractA novel barium antimonite with mixed-valence Sb5+ (Sb1) and Sb3+ (Sb2) cations, Ba2Sb7O13(OH), has been synthesized characterized.Figure optionsDownload full-size imageDownload as PowerPoint slide