Layered indium chalcogenidoantimonates [Me2NH2](2)In2Sb2S7-xSex (x=0, 2.20, 4.20, 7) with tunable band gaps and photocatalytic properties

Two novel indium chalcogenidoantimonates and their quaternary mixed solid solutions with a layered structure of [In2Sb2S7-xSex](n)(2n-) are successfully synthesized under mild solvothermal conditions. The compounds show a red-shift of their optical absorption edges and exhibit tunable photocatalytic activity for degradation of methyl orange (MO) with a shift of optical response from UV to the visible light region, as the proportions of Se increase.