Rhombic dodecahedral Cu2O/Ag-3D Fe3O4 micro-flower composites for water purification under visible light irradiation

In this study, 3D Fe 3 O 4 micro-flowers were synthesized by the self-assembly approach, then rhombic dodecahedral Cu 2 O was successfully loaded onto their surface by wet chemical method . Ag nanocrystals were reduced in situ on the surface of Fe 3 O 4 /Cu 2 O composites to prepare novel Fe 3 O 4 /Cu 2 O/Ag composites. The composites were characterized by SEM, TEM, XRD , XPS, VSM and UV–Vis diffuse reflectance spectroscopy. The effect of Ag nanocrystals on the photocatalytic performance of the Fe 3 O 4 /Cu 2 O composites was investigated by the degradation of methyl orange under visible light irradiation, and the Fe 3 O 4 /Cu 2 O/Ag composites showed higher photocatalytic efficiency than the Fe 3 O 4 /Cu 2 O composites. Photoelectrochemical and PL measurements were carried out to investigate the synergistic effect between the semiconductors and Ag nanocrystals and it was confirmed that the Fe 3 O 4 /Cu 2 O/Ag composites effectively inhibited the recombination of electron-hole pairs, thus improving the photocatalytic activity. The fact that the Fe 3 O 4 /Cu 2 O/Ag composites could be magnetically recycled and that they retained more than 90% of their original activity after six repeated experiments indicates, that they show great potential for wastewater treatment applications.