Polymorphic crystallization of Cu2O compound

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.