By using cyclic and linear sweep voltammetry,the electrochemical deposition behaviors of Mg^2+ and B^3+ in fluorides molten salts of KF-MgF2 and KF-KBF4 at 880℃ were investigated,respectively.The results show that ...By using cyclic and linear sweep voltammetry,the electrochemical deposition behaviors of Mg^2+ and B^3+ in fluorides molten salts of KF-MgF2 and KF-KBF4 at 880℃ were investigated,respectively.The results show that the electrochemical reduction of Mg^2+ is a one-step reaction as Mg^2++2e-→Mg in KF-1%MgF2 molten salt,and the electrochemical reduction of B^3+ is also a one-step reaction as B^3++3e-→B in KF-KBF4 (1%,2% KBF4) molten salts.Both the cathodic reduction reactions of Mg^2+ and B^3+ are controlled by diffusion process.The diffusion coefficients of Mg^2+ in KF-MgF2 molten salts and B^3+ in KF-KBF4 molten salts are 6.8×10^-7 cm^2/s and 7.85×10^-7 cm^2/s,respectively.Moreover,the electrochemical synthesis of MgB2 by co-deposition of Mg and B was carried out in the KF-MgF2-KBF4 (molar ratio of 6:1:2) molten salt at 750℃.The X-ray diffraction analysis indicates that MgB2 can be deposited on graphite cathode in the KF-MgF2-KBF4 molten salt at 750℃.展开更多
基金Project(50804010) supported by the National Natural Science Foundation of ChinaProject(2007CB210305) supported by the National Basic Research Program of China
文摘By using cyclic and linear sweep voltammetry,the electrochemical deposition behaviors of Mg^2+ and B^3+ in fluorides molten salts of KF-MgF2 and KF-KBF4 at 880℃ were investigated,respectively.The results show that the electrochemical reduction of Mg^2+ is a one-step reaction as Mg^2++2e-→Mg in KF-1%MgF2 molten salt,and the electrochemical reduction of B^3+ is also a one-step reaction as B^3++3e-→B in KF-KBF4 (1%,2% KBF4) molten salts.Both the cathodic reduction reactions of Mg^2+ and B^3+ are controlled by diffusion process.The diffusion coefficients of Mg^2+ in KF-MgF2 molten salts and B^3+ in KF-KBF4 molten salts are 6.8×10^-7 cm^2/s and 7.85×10^-7 cm^2/s,respectively.Moreover,the electrochemical synthesis of MgB2 by co-deposition of Mg and B was carried out in the KF-MgF2-KBF4 (molar ratio of 6:1:2) molten salt at 750℃.The X-ray diffraction analysis indicates that MgB2 can be deposited on graphite cathode in the KF-MgF2-KBF4 molten salt at 750℃.