Electrochemical fabrication of NZVI/TiO2 nano-tube arrays photoelectrode and its enhanced visible light photocatalytic performance and mechanism for degradation of 4-chlorphenol

In this study, nano-scale zero-valent iron (NZVI) decorated TiO2 nano-tube arrays (NZVI/TiO2 NTAs) photoelectrode was fabricated through anodization process, followed by galvanostatic electrodeposition strategy. Afterwards, physicochemical properties of the resulting NZVI/TiO2 NTAs samples were systematically studied by SEM, XRD, XPS, IJV vis DRS and photoelectrochemical (PECH) measurements. Results indicated that NZVI/TiO2 NTAs photoelectrode exhibited greatly enhanced visible light absorbance and high photogenerated charge separation efficiency. However, after photocatalytic (PC) reaction, NVZI particles were converted to alpha-Fe2O3 species, which would further improve the visible light absorbance and PC efficiency, which was confirmed by the further enhanced visible light PC performance for decomposition of 4-chlorphenol (4-CP) and generation of.OH radicals. Furthermore, the enhanced visible light mechanism of NZVI/TiO2 NTAs photoelectrode was detailed discussed. This study provides a versatile strategy to fabricate high-efficient catalysts which could be used in the high-toxic and refractory micro-pollutants elimination in water body. (C) 2017 Elsevier B.V. All rights reserved.