Syntheses, Crystal Structures, Ion-Exchange, and Photocatalytic Properties of Two Amine-Directed Ge–Sb–S Compounds

Among numerous heterometallic chalcogenidoantimonates, relatively a few amine-directed Ge–Sb–S compounds have been synthesized. Presented here are the solvothermal syntheses, crystal structures, and ion-exchange, optical, and photocatalytic properties of two novel amine-directed Ge–Sb–S compounds, namely, [CH3NH3]20Ge10Sb28S72·7H2O (1) and [(CH3CH2CH2)2NH2]3Ge3Sb5S15·0.5(C2H5OH) (2). The structure of 1 features an unprecedented two-dimensional Ge–Sb–S double-layer composed of two twofold rotational symmetry-related thick [Ge8Sb28S72]n28n– single layers adhered via vertex-sharing [GeS4] tetrahedra. Compound 2 features a unique [Ge3Sb5S15]n3n– slab perforated with large elliptic-like windows. Remarkably, compound 1 exhibited excellent Cs+ ion-exchange property despite the presence of excess competitive cations, such as Na+, K+, Mg2+, and Ca2+ ions. In addition, compound 1 displayed visible-light-driven photocatalytic activity for degradation of rhodamine B.