The kinetic model of induced codeposition of nickel-molybdenum alloys from ammonium citrate solution was studied on rotating disk electrodes to predict the behavior of the electrode-position. The molybdate (MoO42?) co...The kinetic model of induced codeposition of nickel-molybdenum alloys from ammonium citrate solution was studied on rotating disk electrodes to predict the behavior of the electrode-position. The molybdate (MoO42?) could be firstly electro-chemically reduced to MoO2, and subsequently undergoes a chemical reduction with atomic hydrogen previously adsorbed on the inducing metal nickel to form molybdenum in alloys. The kinetic equations were derived, and the kinetic parameters were obtained from a comparison of experimental results and the kinetic equations. The electrochemical rate constants for discharge of nickel, molybdenum and water could been expressed as k1,(E) = 1.23 × 10?9 CNexp( - 0.198 FE/RT) mol/(dm2 · s), k2 (E) = 3.28 × 10?10 CMoexp ( - 0.208FE/ RT) mol/(dm2 · s) and k3(E) = 1.27 × 10?6 exp ( -0.062FE/ RT) mol/(dm2 · s), where CN and CMo, are the concentrations of the nickel ion and molybdate, respectively, and E is the applied potential vs. saturated calomel electrode (SCE). The codeposition process could be well simulated by this model.展开更多
Co deposition of Ho with Co was studied in dimethylsulfoxide (DMSO) by cyclic voltammetry and potentiostatic deposition at room temperature. The cyclic voltammogram shows that the codeposition of Ho with Co can be at...Co deposition of Ho with Co was studied in dimethylsulfoxide (DMSO) by cyclic voltammetry and potentiostatic deposition at room temperature. The cyclic voltammogram shows that the codeposition of Ho with Co can be attributed to induced codeposition mechanism, for the codeposition potential is more negative than the deposition potential of Co but positive than that of Ho. For the potentiostatic deposition used in Ho Co alloys preparation, the results indicate that in the range of selected concentration the potential is the main factor determining the content of Ho in Ho Co alloys, while the composition of Ho 3+ and Co 2+ in electrolyte solution has less influence. According to the analysis of X ray diffraction, EDAX, and scanning electron microscopy, uniform, compact and amorphous films on Cu can be obtained at -1 8 V (vs.SCE) in 0 165 mol·L -1 Ho(NO 3) -0 135 mol·L -1 CoCl 2 DMSO solution.展开更多
文摘The kinetic model of induced codeposition of nickel-molybdenum alloys from ammonium citrate solution was studied on rotating disk electrodes to predict the behavior of the electrode-position. The molybdate (MoO42?) could be firstly electro-chemically reduced to MoO2, and subsequently undergoes a chemical reduction with atomic hydrogen previously adsorbed on the inducing metal nickel to form molybdenum in alloys. The kinetic equations were derived, and the kinetic parameters were obtained from a comparison of experimental results and the kinetic equations. The electrochemical rate constants for discharge of nickel, molybdenum and water could been expressed as k1,(E) = 1.23 × 10?9 CNexp( - 0.198 FE/RT) mol/(dm2 · s), k2 (E) = 3.28 × 10?10 CMoexp ( - 0.208FE/ RT) mol/(dm2 · s) and k3(E) = 1.27 × 10?6 exp ( -0.062FE/ RT) mol/(dm2 · s), where CN and CMo, are the concentrations of the nickel ion and molybdate, respectively, and E is the applied potential vs. saturated calomel electrode (SCE). The codeposition process could be well simulated by this model.
基金Project supported by Natural Science Foundation of Guangdong Province (011215)
文摘Co deposition of Ho with Co was studied in dimethylsulfoxide (DMSO) by cyclic voltammetry and potentiostatic deposition at room temperature. The cyclic voltammogram shows that the codeposition of Ho with Co can be attributed to induced codeposition mechanism, for the codeposition potential is more negative than the deposition potential of Co but positive than that of Ho. For the potentiostatic deposition used in Ho Co alloys preparation, the results indicate that in the range of selected concentration the potential is the main factor determining the content of Ho in Ho Co alloys, while the composition of Ho 3+ and Co 2+ in electrolyte solution has less influence. According to the analysis of X ray diffraction, EDAX, and scanning electron microscopy, uniform, compact and amorphous films on Cu can be obtained at -1 8 V (vs.SCE) in 0 165 mol·L -1 Ho(NO 3) -0 135 mol·L -1 CoCl 2 DMSO solution.
