Design and synthesis of metal hydroxide three-dimensional inorganic cationic frameworks.

Three-dimensional (3D) cationic frameworks are rare but crucial host materials with vast industrial applications. However, the controlled synthesis of 3D inorganic cationic framework (ICF) materials still remains a challenge. Here, we develop a new strategy to construct 3D inorganic cationic frameworks by octahedral metal-hydroxide (M(OH)6) unit induced reconstruction of layered rare-earth hydroxides. Based on this strategy, a large family (>187 members) of 3D-ICF with a general formula: RE12(OH)18((RE1-x-y,MxM'y)(OH)6)4·ACl6 (RE = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y; M = Al, Cr; M' = Mg, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn; A = Na, K) were achieved. This newly constructed strategy would greatly promote the development of 3D inorganic cationic materials. Furthermore, the discovery of this new family of cationic frameworks would pave the way for the potential application of cationic materials in different sorts of fields.