The effects of temperature, nickel concentration and current density on the current efficiency and the electrolyzer voltage were investigated in the process of electrowinning nickel. The results show that the current ...The effects of temperature, nickel concentration and current density on the current efficiency and the electrolyzer voltage were investigated in the process of electrowinning nickel. The results show that the current efficiency is above 90% under the various experimental conditions, and the electrolyzer voltage is less than that of traditional electrolyzer system. Therefore, the optimized parameters, i.e. temperature of 50 ℃, current density of 400 A/m 2, are determined. It is also elucidated that anodic product is high valent nickel compound in the process of electrodeposition in terms of X-ray diffraction and chemical analysis. The amount of solid product formed on the electrode surface decreases with an increase in ammonium chloride concentration by cyclic voltammetry analysis. It is also indicated that the anodic gas species are mainly composed of nitrogen by vapor phase chromatograph.展开更多
Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lover voltage. The ...Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lover voltage. The morphologies of template and copper nano-wires arrays were characterized by means of field emission scanning electron microscope (FESEM) and the crystal structure of copper nano-wires was determined by means of X-ray diffraction. The results indicate that copper nano-wires hold the preferred crystalline orientation along (111), (200), (220) and (331) crystal faces during growth, and the growth of copper nano-wires in the nano-holes of the template is homogenous and continuous.展开更多
文摘The effects of temperature, nickel concentration and current density on the current efficiency and the electrolyzer voltage were investigated in the process of electrowinning nickel. The results show that the current efficiency is above 90% under the various experimental conditions, and the electrolyzer voltage is less than that of traditional electrolyzer system. Therefore, the optimized parameters, i.e. temperature of 50 ℃, current density of 400 A/m 2, are determined. It is also elucidated that anodic product is high valent nickel compound in the process of electrodeposition in terms of X-ray diffraction and chemical analysis. The amount of solid product formed on the electrode surface decreases with an increase in ammonium chloride concentration by cyclic voltammetry analysis. It is also indicated that the anodic gas species are mainly composed of nitrogen by vapor phase chromatograph.
文摘Highly ordered and porous anodic aluminum oxide templates were prepared. The ordered copper nanowires arrays were assembled in nano-holes of the template by alternating current electrodeposition at lover voltage. The morphologies of template and copper nano-wires arrays were characterized by means of field emission scanning electron microscope (FESEM) and the crystal structure of copper nano-wires was determined by means of X-ray diffraction. The results indicate that copper nano-wires hold the preferred crystalline orientation along (111), (200), (220) and (331) crystal faces during growth, and the growth of copper nano-wires in the nano-holes of the template is homogenous and continuous.
