Fabrication of p-NiO/n-TiO2 nano-tube arrays photoelectrode and its enhanced photocatalytic performance for degradation of 4-chlorphenol

In the study, we report that p-type NiO (p-NiO) nanoparticles were successfully decorated onto the of n-type TiO2 nano-tube arrays (n-TiO2 NTAs) photoelectrode by anodization process, followed by electrodeposition strategy in the presence of NiSO4 electrolyte. After then, the samples were studied by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In addition, the optical and photoelectrochemical (PECH) properties of p-NiO/n-TiO2 NTAs were recorded through ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) curves, respectively. Furthermore, We evaluated the photocatalytic (PC) degradation of 4-chlorphenol and the enhanced PC mechanism was also discussed. Results suggest that p-NiO/n-TiO2 NTAs photoelectrode exhibited higher PC activities than that of pristine TiO2 NTAs owing to its higher photogeneration electrons-holes (e/h(+)) pairs separation efficiency and light absorbance. As a consequence, the p-NiO/n-TiO2 NTAs photoelectrode could be applied in degradation of organic pollutants and wastewater purification. (C) 2017 Elsevier B.V. All rights reserved.