Mild solvothermal syntheses and characterizations of four quaternary layered sulfides AAgCdS(2) (A = K, Rb, Cs) and Cs2Cu2Cd2S4

摘要

Four layered quaternary sulfides IkAgCdS(2) (1), RbAgCdS2 (2), CsAgCdS2 (3), and Cs2Cu2Cd2S4 (4) have been successfully synthesized by mild solvothermal methods by employing excess sulfur as a mineralizer. Compound 1 possesses anionic [AgCdS2](n)(n)(-) double layers. Compounds 2 and 3 are isostructural and contain anionic [AgCdS2](n)(n)(-) single layers. Although both of the two structures are constructed by edge-sharing [MS4] (M = Ag/Cd) tetrahedral units, their condensation behaviors are totally different. The structure of 4 consists of infinite [Cd2S4](n)(4n-) chains and [CuS2](2-) dumbbells that linked to form [Cu2Cd2S4](n)(2n-) layers. According to the UV-vis diffuse reflectance experiments, the band gaps of the title compounds are 1.92 eV (1), 2.16 eV (2), 2.42 eV (3), and 2.23 eV (4). Additionally, the photo-electrochemical experiments indicate that compounds 2 and 3 exhibit excellent photocurrent responsive properties. (C) 2020 Elsevier B.V. All rights reserved.