Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide (CeO2) were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electro...Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide (CeO2) were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.展开更多
Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique...Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy(EDXS), anode polarization curves, quasi-stationary polarization(Tafel) curves, electrochemical impedance spectroscopy(EIS), scanning electron microscopy(SEM), and X-ray diffraction(XRD). Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential(0.610 V at 500 A/m2) for oxygen evolution, the best electrocatalytic activity, the longest service life(360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2), and the lowest cell voltage(2.75 V at 500 A/m2). Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.展开更多
β-PbO2 electrodes were prepared by electro-deposition and characterized by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and linear sweep voltammetry.We confirmed pure β-PbO2 crysta...β-PbO2 electrodes were prepared by electro-deposition and characterized by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and linear sweep voltammetry.We confirmed pure β-PbO2 crystals were on the electrode and it had a high oxygen evolution potential.The photoactivity and photoelectrochemical(PEC) properties of the β-PbO2 electrode were investigated under visible light irradiation(λ 〉 420 nm) for the decolorization of Methylene Blue.Pseudo first-order kinetics parameter(Kapp) for dye decolorization using the β-PbO2 electrode achieved 6.71×10-4 min-1 under visible light irradiation,which indicated its excellent visible light-induced photoactivity.The Kapp of the PEC process was as much as 1.41×10-3 min-1 and was 1.71 times that of visible light irradiation or electrolysis even in the presence of the β-PbO2 electrode.A significant synergetic effect was observed in the PEC system.We also employed TiO2 modified β-PbO2 electrodes in this test,which revealed that the TiO2 immobilized on the β-PbO2 electrode inhibited the visible light-induced PEC efficiency despite the amount of TiO2 used for electrode preparation.The β-PbO2 electrode was also superior to the dimensionally stable anode(Ti/Ru0.3Ti0.7O2) in visible light-induced photoactivity and PEC efficiency.展开更多
基金Project(50964008)supported by the National Natural Science Foundation of ChinaProject(2010287)supported by Analysis and Testing Foundation of Kunming University of Science and Technology,China
摘要Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide (CeO2) were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.
基金Projects(51004056,51004057)supported by the National Natural Science Foundation of ChinaProject(KKZ6201152009)supported by the Opening Foundation of Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences+2 种基金Project(2010ZC052)supported by the Applied Basic Research Foundation of Yunnan Province,ChinaProject(20125314110011)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,ChinaProject(2010247)supported by Analysis&Testing Foundation of Kunming University of Science and Technology,China
摘要Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy(EDXS), anode polarization curves, quasi-stationary polarization(Tafel) curves, electrochemical impedance spectroscopy(EIS), scanning electron microscopy(SEM), and X-ray diffraction(XRD). Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential(0.610 V at 500 A/m2) for oxygen evolution, the best electrocatalytic activity, the longest service life(360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2), and the lowest cell voltage(2.75 V at 500 A/m2). Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.
基金supported by a GRF grant (No.CUHK477610) of the Research Grants Council of Hong Kong SAR Governmentthe National Natural Science Foundation of China (No. 50708037)
摘要β-PbO2 electrodes were prepared by electro-deposition and characterized by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and linear sweep voltammetry.We confirmed pure β-PbO2 crystals were on the electrode and it had a high oxygen evolution potential.The photoactivity and photoelectrochemical(PEC) properties of the β-PbO2 electrode were investigated under visible light irradiation(λ 〉 420 nm) for the decolorization of Methylene Blue.Pseudo first-order kinetics parameter(Kapp) for dye decolorization using the β-PbO2 electrode achieved 6.71×10-4 min-1 under visible light irradiation,which indicated its excellent visible light-induced photoactivity.The Kapp of the PEC process was as much as 1.41×10-3 min-1 and was 1.71 times that of visible light irradiation or electrolysis even in the presence of the β-PbO2 electrode.A significant synergetic effect was observed in the PEC system.We also employed TiO2 modified β-PbO2 electrodes in this test,which revealed that the TiO2 immobilized on the β-PbO2 electrode inhibited the visible light-induced PEC efficiency despite the amount of TiO2 used for electrode preparation.The β-PbO2 electrode was also superior to the dimensionally stable anode(Ti/Ru0.3Ti0.7O2) in visible light-induced photoactivity and PEC efficiency.