Bi2O2SO4, a new representative of the grandreefite structure type

Single-phase polycrystalline bismuth oxysulfate, Bi2O2SO4, has been prepared via low-temperature reaction between Bi2O2CO3 and (NH4)2SO4. The compound is monoclinic (C2/m, a ​= ​14.1659(4) Å, b ​= ​4.2344(1) Å, c ​= ​8.2100(2) Å, β ​= ​106.7201(8)°, V ​= ​471.65(2) Å3) and isostructural to isoelectronic Pb2F2SO4 and to isolobal Ln2O2SO4. Upon heating, it decomposes at ~550 ​°C into the Bi28O32(SO4)10 which is stable until ~775 ​°C. DFT calculations predict it to be a wide-gap semiconductor. The bismuth oxysulfate, Bi2O2SO4, has been prepared phase-pure by a low-temperature stepwise exchange reaction between Bi2O2CO3 and (NH4)2SO4. [Display omitted] •Bi2O2SO4 has been prepared via a low-temperature exchange route.•The compound is isostructural to Ln2O2SO4 and Pb2F2SO4.•The exchange solid-state route is an efficient soft approach to the compound.