Morphology transformation of Cu2O by adding TEOA and their antibacterial activity

Cu2O polyhedral particles and hollow spheres were successfully synthesized by adjusting the concentration of triethanolamine (TEOA). The as-prepared samples were structurally characterized by the scanning electron microscope (SEM), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM). The results revealed that the solid polyhedral Cu2O with sizes ranging from 70 to 150 nm was in good crystallization. The diameter of the hollow Cu2O spheres increased to 350–450 nm. It was found that the sizes and morphologies of the products could be significantly affected by the concentration of TEOA. And the morphology of Cu2O transformed from solid polyhedrons to hollow spheres with the further enrichment of TEOA concentration. A possible mechanism was proposed to explain the formation of the hollow Cu2O spheres. In addition, we investigated the antibacterial activities of the samples. It was demonstrated that the hollow Cu2O sphere exhibited better antibacterial activities for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) compared with the solid polyhedral Cu2O.