Solvothermal syntheses, characterizations and photocatalytic properties of two copper-rich thiostannates

[Display omitted] •Two copper-rich thiostannates Rb4Cu8Sn3S12 (1) and (H3O)RbCu6Sn2S8 (2) were synthesized solvothermally.•Compound 1 possesses a three-dimensional structure containing [Cu8S12]16- icosahedral clusters and compound 2 displays a dual-channel structure.•Compound 2 possesses the highest Cu+/Sn4+ molar ratio (3.0) in the known three-dimensional open-framework sulfides and exhibits good photocatalytic performance. Two copper-rich thiostannates Rb4Cu8Sn3S12 (1) and (H3O)RbCu6Sn2S8 (2) were synthesized solvothermally. Compound 1 possesses a three-dimensional structure containing [Cu8S12]16- icosahedral clusters. Compound 2 displays a dual-channel structure and the Cu+/Sn4+ molar ratio of this compound is the highest in the known three-dimensional open-framework sulfides. The optical properties and photocatalytic degradation performances for methylene blue of 1 and 2 were also studied.