Facile CeO2 nanoparticles deposition on Si-nanowires: application to the rhodamine B photodegradation under visible light

In this work, cerium dioxide nano-particles (CeO2-NPs) were deposited by chemical electroless deposition process on silicon nanowires (Si-NWs) elaborated by metal-assisted chemical etching. The obtained thin films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), photoluminescence (PL), X-ray photoelectron spectrometry (XPS) and UV–Vis spectrophotometry. The Si-NWs/CeO2-NPs films were successfully applied as photocatalysts for the oxidation of Rhodamine B (Rh B), a recalcitrant dye under visible irradiation. The films showed a higher photocatalytic performance with a quasi-total discoloration within 75 min against only 67% for Si-NWs. The radical trapping tests showed that the electrons (e−), •OH, O2•− and holes (h+) are the main species involved in the Rh B degradation; a reaction mechanism was suggested and discussed. This work provides a new alternative to develop an efficient photocatalyst to eliminate emerging pollutants from the aquatic environment.