Surface tuning of the photoelectrochemical properties of oblique angle co-sputtered Zn_xFe_yO films by Fe concentration

Complex three-dimensional nanosheet structure of Zn_xFe_yO was prepared by highly stable co-sputtering oblique angle deposition. Scanning electron microscopy was employed to observe surface morphology evolution of Zn_xFe_yO with different Fe concentrations. X-ray diffraction was employed to analyze compositions of ZnO, ZnFe₂O₄, and ZnFe₂O₄/Fe₂O₃ with Fe doping. Furthermore, specific nanostructures of Zn_xFe_yO decreased band gap and increased visible-light absorption ability. The ZnFe₂O₄/Fe₂O₃ sample exhibited higher photocatalytic efficiency than those of other films for the degradation of methylene blue. Addition of Fe led to the enhancement of photoelectrochemical properties of ZnFe₂O₄/Fe₂O₃ compared to pure ZnO and Fe₂O₃, and photocurrent response of ZnFe₂O₄/Fe₂O₃ was ~10 times than that of pure ZnO at constant potential of −0.2 V (vs. Ag/AgCl).