Polymorphic crystallization of Cu2O compound

Abstract

Cu₂O can crystallize into various polymorphs, such as cubes, rhombic dodecahedra, branching structures, and hopper cubes, instead of thermodynamically stable octahedra by designed kinetic-control routes instead of traditional thermodynamic control. The present results confirmed that Cu₂O polymorphs have distinct physical and chemical properties, and morphology changes can occur due to polymorphic transitions in a kinetics-controllable reaction system. Both thermodynamic and kinetic factors on these polymorphism systems are believed to be significant for developing a polymorphism–property relationship, ultimately guiding the appropriate material selection for specific applications. Furthermore, we took Cu₂O as an example to illustrate the development of “polymorphism” in modern materials science: polymorphism is an intrinsic physicochemical characteristic, and involves varying growth shapes, phase transformation and variation of physical properties. These findings can provide new insight to polymorphism–performance correlation and kinetic–thermodynamic control synthesis.