The electrode process of Y^(3+)ion on molybdenum and nickel electrodes has been studied by cyclic voltammetry and chronopotentiometry in the YCl_3-NaCl-KCl melt.The overall charge transfer process is a two-step reacti...The electrode process of Y^(3+)ion on molybdenum and nickel electrodes has been studied by cyclic voltammetry and chronopotentiometry in the YCl_3-NaCl-KCl melt.The overall charge transfer process is a two-step reaction:Y^(3+)+e=Y^(2+);Y^(2+)+2e=Y.Yttrium reduced on the nickel electrode can form a series of Ni-Y alloys.X-ray diffraction analysis was employed to determine the alloy compositions formed under different con- ditions.展开更多
采用包覆的方法制备出MO/C型复合电极材料,通过X射线衍射(XRD)对复合材料的结构组成进行表征分析,另外通过循环伏安法、计时电位法和交流阻抗技术对复合电极材料在6 M KOH溶液中的电化学电容性能进行考查。结果表明:包覆了过渡金属锰氧...采用包覆的方法制备出MO/C型复合电极材料,通过X射线衍射(XRD)对复合材料的结构组成进行表征分析,另外通过循环伏安法、计时电位法和交流阻抗技术对复合电极材料在6 M KOH溶液中的电化学电容性能进行考查。结果表明:包覆了过渡金属锰氧化物的复合电极材料在0.5 A/g的电流密度下比电容最高可达218.3 F/g。此外,MO/C型复合电极材料表现出较好的功率性能,当电流密度增加到5 A/g,其比电容值达到168.0 F/g,其电容保持率为77.0%,表明这是一种很有前景的电极材料。展开更多
Sputtering method was used to prepare Ni-Mo alloy electrodes for hydrogen production in alkaline solution. The influences of the working pressure during deposition and the substrate temperature on the electrochemical ...Sputtering method was used to prepare Ni-Mo alloy electrodes for hydrogen production in alkaline solution. The influences of the working pressure during deposition and the substrate temperature on the electrochemical behavior of electrode were characterized by steady-state polarization plot and Tafel polarization curve measurements. And the physical properties of electrodes were characterized by XRD, SEM, AFM and EDS. It is found that the overpotential is significantly influenced by the working pressure which affects critically the electrode surface morphology, and two Tafel regions are observed for each sample. The overpotential value does not change very much with the substrate temperature. The XRD results indicates that the electrodes should be considered nanocrystalline. Thornton model for the microstructure of sputter-deposited electrodes is referred to explain the observed microstructure change.展开更多
Ni-Fe-Mo-Co alloy electrode was prepared in a citrate solution by electrodeposition, and then Mo and Fe were partially leached out from the electrode in 30% KOH solution. The unique surface micromorphology of a hive-l...Ni-Fe-Mo-Co alloy electrode was prepared in a citrate solution by electrodeposition, and then Mo and Fe were partially leached out from the electrode in 30% KOH solution. The unique surface micromorphology of a hive-like structure was obtained with an average pore size of about 50 nm. The electrode has a very large real surface area and a stable structure. The effects of sodium molybdate concentration on the composition, surface morphology, and structure of electrodes were analyzed by EDS, SEM and XRD. The polarization curves of the different electrodes show that the catalytic activity of electrodes is strongly correlated with the mole fraction of alloy elements (Ni, Fe, Mo, Co), and the addition of cobalt element to Ni-Fe-Mo alloy improves the catalytic activity. The Ni35.63Fe24.67Mo23.52Co16.18 electrode has the best activity for hydrogen evolution reaction(HER), with an over-potential of 66.2 mV, in 30% KOH at 80 ℃ and 200 mA/cm2. The alloy maintains its good catalytic activity for HER during continuous or intermittent electrolysis. Its electrochemical activity and catalytic stability are much higher than the other iron-group with Mo alloy electrodes.展开更多
文摘The electrode process of Y^(3+)ion on molybdenum and nickel electrodes has been studied by cyclic voltammetry and chronopotentiometry in the YCl_3-NaCl-KCl melt.The overall charge transfer process is a two-step reaction:Y^(3+)+e=Y^(2+);Y^(2+)+2e=Y.Yttrium reduced on the nickel electrode can form a series of Ni-Y alloys.X-ray diffraction analysis was employed to determine the alloy compositions formed under different con- ditions.
基金Project(2003CB214501) supported by the National Basic Research Program of China Project(48010) supported by the Excellent Doctor’s Science and Technology Innovation Foundation of Beijing Jiaotong University, China
文摘Sputtering method was used to prepare Ni-Mo alloy electrodes for hydrogen production in alkaline solution. The influences of the working pressure during deposition and the substrate temperature on the electrochemical behavior of electrode were characterized by steady-state polarization plot and Tafel polarization curve measurements. And the physical properties of electrodes were characterized by XRD, SEM, AFM and EDS. It is found that the overpotential is significantly influenced by the working pressure which affects critically the electrode surface morphology, and two Tafel regions are observed for each sample. The overpotential value does not change very much with the substrate temperature. The XRD results indicates that the electrodes should be considered nanocrystalline. Thornton model for the microstructure of sputter-deposited electrodes is referred to explain the observed microstructure change.
基金Project(20374021) supported by the National Natural Science Foundation of China
文摘Ni-Fe-Mo-Co alloy electrode was prepared in a citrate solution by electrodeposition, and then Mo and Fe were partially leached out from the electrode in 30% KOH solution. The unique surface micromorphology of a hive-like structure was obtained with an average pore size of about 50 nm. The electrode has a very large real surface area and a stable structure. The effects of sodium molybdate concentration on the composition, surface morphology, and structure of electrodes were analyzed by EDS, SEM and XRD. The polarization curves of the different electrodes show that the catalytic activity of electrodes is strongly correlated with the mole fraction of alloy elements (Ni, Fe, Mo, Co), and the addition of cobalt element to Ni-Fe-Mo alloy improves the catalytic activity. The Ni35.63Fe24.67Mo23.52Co16.18 electrode has the best activity for hydrogen evolution reaction(HER), with an over-potential of 66.2 mV, in 30% KOH at 80 ℃ and 200 mA/cm2. The alloy maintains its good catalytic activity for HER during continuous or intermittent electrolysis. Its electrochemical activity and catalytic stability are much higher than the other iron-group with Mo alloy electrodes.
