Two silver chalcogenidoantimonates synthesized in piperazine and their high performances for visible-light driven Cr(VI) reduction

In the synthesis of organic hybrid metal chalcogenides, piperazine (pip) has been widely applied as a template or charge-balancing agent in the structure assembly, but application of piperazine as a solvent to synthesize organic hybrid metal chalcogenides has not been reported. In this work, two new two-dimensional layered organic hybrid silver chalcogenidoantimonates, namely [pipH₂]_0.5[Ag₂SbS₃] (1), [pipH₂]_0.5[Ag₂SbSe₃] (2), have been synthesized by using piperazine as reaction medium. Both compounds possess the similar honeycombed anionic bilayers, and the biprotonated piperazine cations are resided between the bilayers. Thermal stabilities and optical properties of compounds 1 and 2 have been studied. Moreover, compounds 1 and 2 exhibited excellent photocatalytic activities for reducing aqueous Cr(VI) under visible light irradiation.