Four New Sb-based Orthophosphates: Cation Regulation to Investigate Diversified Structural Architecture.

ABSTRACT

In the work, four new Sb-based phosphates, K4 (SbO2 )5 (PO4 )3 , Rb(SbO2 )2 PO4 , Rb3 (SbO2 )3 (PO4 )2 and Cs3 (SbO2 )3 (PO4 )2 (H2 O)1.32 , were successfully synthesized by a high-temperature melt method. Among them, Rb(SbO2 )2 PO4 and Rb3 (SbO2 )3 (PO4 )2 are the first reported examples of Rb-containing alkali metal Sb-based phosphates. They show three-dimensional (3D) frameworks composed of [Sb8 P4 O30 ]∞ layer for K4 (SbO2 )5 (PO4 )3 and [Sb6 P2 O20 ]∞ layer for Rb(SbO2 )2 PO4 , and 2D lamellar structure composed of [Sb3 P2 O10 ]∞ for Rb3 (SbO2 )3 (PO4 )2 and Cs3 (SbO2 )3 (PO4 )2 (H2 O)1.32 . A detailed structural comparison shows that the structure dimensions for them transfer from 1D to complex 3D framework with the increase of (Sb+P)/O ratio, which affects performances of the compounds. Optical property and energy band structure calculations were also carried out based on the density functional theory (DFT). The present study enriches the diversity of Sb-based phosphates and paves the way for further explore their optical properties in the future.