Syntheses, Crystal Structures, and Optical and Photocatalytic Properties of Four Small-Amine-Molecule-Directed M–Sn–Q (M = Zn, Ag; Q = S, Se) Compounds

Abstract

By utilizing different small amine molecules as structure-affecting agents (SAAs) and charge-balancing agents (CBAs), four new M–Sn–Q (M = Zn, Ag; Q = S, Se) compounds with the anionic architectures ranging from a one-dimensional (1D) chain to a three-dimensional (3D) network have been solvothermally synthesized. Compound [(Me) 2 NH 2 ] 2 ZnSn 3 Se 8 ( 1 ) features an anionic (4,4) layer of [ZnSn 3 Se 8 ] n 2 n – and represents a rare [ZnSn 3 Se 10 ] T2 cluster-based two-dimensional Zn–Sn–Se compound directed by organic amine. Compound [NH 4 ] 3 AgSn 3 Se 8 ( 2 ) contains infinite linear anionic chains of [AgSn 3 Se 8 ] n 3 n – . Compound [CH 3 NH 3 ] 2 [H 3 O]Ag 5 Sn 4 Se 12 ·C 2 H 5 OH ( 3 ) exhibits a 3D open-framework structure of [Ag 5 Sn 4 Se 12 ] n 3 n – with intersecting 3D channels. Compound [CH 3 NH 3 ] 6 Ag 12 Sn 6 S 21 ( 4 ) features a 3D framework structure with 1D channels filled by [CH 3 NH 3 ] + cations. The most fascinating structural feature of compound 4 is that a complex 3D [Ag 12 S 17 ] n 22 n – anionic network exists based on the combination of three types of basic building blocks of [AgS 2 ] dumbbells, [AgS 3 ] triangles, and [AgS 4 ] tetrahedra. The thermal stabilities, optical properties of the title compounds 1 – 4, as well as the theoretical band structure and density of states of compound 4 have been studied. Moreover, compound 3 displayed visible-light-driven photocatalytic activity for the degradation of crystal violet.