A facile strategy to porous materials: Coordination-assisted heterogeneous dissolution route to the spherical Cu2O single crystallites with hierarchical pores

Porous Cu2O single crystalline spheres with the sizes of 60–100 nm were synthesized by a facile method which involved the reactions based on the chemical properties between NH3, OH−, Cu2+ and Cu2O. The presence of ammonia and the precise control of the molar ratios of the reactants are crucial factors leading to the porous structured Cu2O. The single crystalline framework of the porous Cu2O spheres was produced by the heterogeneous dissolution of the freshly formed single crystalline Cu2O spheres which is similar to the wet chemical etching. As a result, their crystalline character was preserved. Based on the designed experiments and corresponding morphologies of the resultants, the formation mechanism is proposed as coordination-assisted heterogeneous dissolution (CHD). The porous Cu2O possess remarkable photocatalytic activity under visible light irradiation. This strategy to porous materials via CHD is proved to be convenient and efficient, and provide a potential way to achieve porous structures even for other materials.