Construction of graphite/TiO2ickel foam photoelectrode and its enhanced photocatalytic activity

摘要

Graphite/TiO2ickel foam photoelectrode was constructed through a modified sol-gel method, followed by coating procedure. Morphology, structure and optical property of the as-prepared photoelectrode was characterized via transmission electron microscopy (TEM), scanning electrons microscopy (SEM), Xray photoelectron microscopy (XPS), X-ray diffraction (XRD) and UV-vis diffuse reflection spectroscopy (DRS). Results indicated that nickel foam framework was partly covered by graphite/TiO2 and the crystallite sizes of anatase TiO2 were found to be about 10 nm. C elements were incorporated into the lattice of TiO2 nanoparticles through replacing titanium atom. Graphite/TiO(2)inickel foam photoelectrode showed the enhancement of light absorption in entire UV-vis regions. Besides, the photoelectrochemical performances of the graphite/TiO2ickel foam electrode were studied by transient photocurrent response (TPR), open circuit voltage (OCV) and electrochemical impedance spectroscopy (EIS). Moreover, photodecomposition properties of the electrode were evaluated by the generation of hydroxyl ((OH)-O-center dot) radicals, photocatalytic (PC) and photoelectrocatalytic (PEC) degradation of methyl orange (MO). The graphite/TiO2ickel foam electrode revealed high transient photogenerated current of 0.054 mAcm(-2), open circuit photovoltage of 0.32 mVcm(-2), yield of (OH)-O-center dot radicals, PC activity of 85.1% and PEC activity of 99.8% for removal of MO. The improved PEC efficiency could be mainly ascribed to the coupled graphite, nickel foam support and applied bias voltage, which could not only enhance the UV-vis light absorption, but also accelerate the charges separation and transfer. (C) 2016 Elsevier B.V. All rights reserved.