Nucleation mechanism and technological process for Ni-Fe co-deposition with a relatively high Fe^(2+)concentration surrounded were described,and the effects of Fe^(2+) concentration,solution pH,temperature,and sodium ...Nucleation mechanism and technological process for Ni-Fe co-deposition with a relatively high Fe^(2+)concentration surrounded were described,and the effects of Fe^(2+) concentration,solution pH,temperature,and sodium dodecyl sulfonate concentration were investigated.Electrochemical experiments demonstrate that iron's electrodeposition plays a leading role in the Ni-Fe co-deposition process,and the co-deposition nucleation mechanism accords with a progressive nucleation.Temperature increase does favor in increasing nickel content in the ferronickel(Ni-Fe co-deposition products),while Fe^(2+) concentration increase does not.When solution pH is higher than 3.5,nickel content in the ferronickel decreases with pH because of the hydrolysis of Fe^(2+).With the current density of 180 A/m^2,Na_2SO_4 concentration of 100 g/L and Ni^(2+) concentration of 60 g/L,a smooth ferronickel deposit containing 96.21% Ni can be obtained under the conditions of temperature of 60 °C,Fe^(2+) concentration of 0.3 g/L,solution pH of 3 and sodium dodecyl sulfonate concentration of 40 mg/L.展开更多
Recent efforts have focused on the fabrication and application of three- dimensional （3-D） nanoarchitecture electrodes, which can exhibit excellent electrochemical performance. Herein, a novel strategy towards the d...Recent efforts have focused on the fabrication and application of three- dimensional （3-D） nanoarchitecture electrodes, which can exhibit excellent electrochemical performance. Herein, a novel strategy towards the design and synthesis of size- and thickness-tunable two-dimensional （2-D） MnO2 nanosheets on highly conductive one-dimensional （l-D） backbone arrays has been developed via a facile, one-step enhanced chemical bath deposition （ECBD） method at a low temperature （-50 ℃）. Inclusion of an oxidizing agent, BrO3-, in the solution was crucial in controlling the heterogeneous nucleation and growth of the nanosheets, and in inducing the formation of the tailored and uniformly arranged nanosheet arrays. We fabricated supercapacitor devices based on 3-D MnO2 nanosheets with conductive Sb-doped SnO2 nanobelts as the backbone. They achieved a specific capacitance of 162 F·g-1 at an extremely high current density of 20 A·g% and good cycling stability that shows a capacitance retention of -92% of its initial value, along with a coulombic efficiency of almost 100% after 5,000 cycles in an aqueous solution of I M Na2SO4. The results were attributed to the unique hierarchical structures, which provided a short diffusion path of electrolyte ions by means of the 2-D sheets and direct electrical connections to the current collector by 1-D arrays as well as the prevention of aggregation by virtue of the well-aligned 3-D structure.展开更多
基金Project(51574135)supported by the National Natural Science Foundation of ChinaProject(KKPT201563022)supported by Collaborative Innovation Center of Kunming University of Science and Technology,China
文摘Nucleation mechanism and technological process for Ni-Fe co-deposition with a relatively high Fe^(2+)concentration surrounded were described,and the effects of Fe^(2+) concentration,solution pH,temperature,and sodium dodecyl sulfonate concentration were investigated.Electrochemical experiments demonstrate that iron's electrodeposition plays a leading role in the Ni-Fe co-deposition process,and the co-deposition nucleation mechanism accords with a progressive nucleation.Temperature increase does favor in increasing nickel content in the ferronickel(Ni-Fe co-deposition products),while Fe^(2+) concentration increase does not.When solution pH is higher than 3.5,nickel content in the ferronickel decreases with pH because of the hydrolysis of Fe^(2+).With the current density of 180 A/m^2,Na_2SO_4 concentration of 100 g/L and Ni^(2+) concentration of 60 g/L,a smooth ferronickel deposit containing 96.21% Ni can be obtained under the conditions of temperature of 60 °C,Fe^(2+) concentration of 0.3 g/L,solution pH of 3 and sodium dodecyl sulfonate concentration of 40 mg/L.
文摘Recent efforts have focused on the fabrication and application of three- dimensional （3-D） nanoarchitecture electrodes, which can exhibit excellent electrochemical performance. Herein, a novel strategy towards the design and synthesis of size- and thickness-tunable two-dimensional （2-D） MnO2 nanosheets on highly conductive one-dimensional （l-D） backbone arrays has been developed via a facile, one-step enhanced chemical bath deposition （ECBD） method at a low temperature （-50 ℃）. Inclusion of an oxidizing agent, BrO3-, in the solution was crucial in controlling the heterogeneous nucleation and growth of the nanosheets, and in inducing the formation of the tailored and uniformly arranged nanosheet arrays. We fabricated supercapacitor devices based on 3-D MnO2 nanosheets with conductive Sb-doped SnO2 nanobelts as the backbone. They achieved a specific capacitance of 162 F·g-1 at an extremely high current density of 20 A·g% and good cycling stability that shows a capacitance retention of -92% of its initial value, along with a coulombic efficiency of almost 100% after 5,000 cycles in an aqueous solution of I M Na2SO4. The results were attributed to the unique hierarchical structures, which provided a short diffusion path of electrolyte ions by means of the 2-D sheets and direct electrical connections to the current collector by 1-D arrays as well as the prevention of aggregation by virtue of the well-aligned 3-D structure.
