A novel fabrication of Cu 2 O@Cu 7 S 4 core-shell micro/nanocrystals from Cu 2 O temples and enhanced photocatalytic activities

Uniform and monodispersed Cu2[email protected]7S4 core-shell micro/nanocrystals have been synthesized successfully at room temperature via a simple chemical etching reaction, using Cu2O as sacrificial template. The structure and properties of the crystals were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS). The photocatalytic activity of the Cu2[email protected]7S4 crystals was evaluated by photocatalytic decolorization of MeO (methyl orange) aqueous solution at ambient temperature under visible-light irradiation. The results show that the as-prepared Cu2[email protected]7S4 crystals revealed core-shell structure, which maintained the same morphology with corresponding template and were composed of cuboctahedron Cu7S4 shell and active Cu2O core. Due to the unique Cu2[email protected]7S4 core-shell structure, the crystals exhibit enhanced photocatalytic activity than that of the pure Cu2O crystals, and the photocatalytic activity of different R crystals is diverse from each other. A possible formation mechanism has been proposed.