Enhancement of photocatalytic activity in ZnO NWs array due to Fe2O3 NPs electrodeposited on the nanowires surface: The role of ZnO-Fe2O3 interface

In this work, the electrodeposition technique was explored to obtain: (i) ZnO film, (ii) ZnO microrods (ZnO MRs), and (iii) ZnO nanowires array (ZnO NWA) on a slide of indium tin oxide coated glass as substrate. The ZnO NWs were decorated with Fe2O3 nanoparticles (Fe2O3 NPs). Thus, a two-step electrodeposition method was per-formed. In the first step, ZnCl2 aqueous solution was employed to rise the ZnO NWs; The molar concentration, temperature, and time were explored to understand the influence of parameters on structural properties and morphology. In the second step, the Fe2O3 NPs were incorporated on the surface of nanowires by electrodepo-sition of FeCl3 (200 mu M) aqueous solution for 1 min. This was confirmed by electron microscopy. In addition, the X-ray photoelectron spectroscopy (XPS) probed that the attachment of Fe2O3 NPs on ZnO NWs induced a sig-nificant increment in the density of oxygen defects. The photocatalytic activity of samples was measured by photodegradation of methylene blue (MB). Findings proved that the ZnO-Fe2O3 heterostructure enhanced the photocatalytic activity due to the charge transfer mechanism at the interface. The Fe2O3 NPs prevent the degradation of ZnO NWs across photocatalytic cycles of the MB solution, showing a reduction in the global degradation efficiency of 1.93% after 3 cycles.

Automated summary

In this study, electrodeposition technique was used to fabricate ZnO film, ZnO microrods, and ZnO nanowires array decorated with Fe2O3 nanoparticles. The ZnO-Fe2O3 heterostructure exhibited enhanced photocatalytic activity.