温度对掺杂球形Ni(OH)_2质子扩散的影响

应用微电极恒电位阶跃法研究了在Ni(OH) 2 电极的阳极及阴极过程反应中 ,温度对球形Ni(OH) 2 的质子扩散系数和表观扩散活化能的影响 .研究表明 ,于Ni(OH) 2 中掺杂Co和Co +Zn后可降低其阳极和阴极过程的表观扩散活化能 ,增大质子扩散系数 ,掺Co的效果更加明显 ,而掺Zn则增大表观扩散活化能 ,降低了扩散系数 .这说明前者的掺入其作用是降低了质子扩散阻力使电极的反应活性增加、而后者的掺入则是增大了质子的扩散阻力而使电极反应活性降低 .

Effects of Temperature on the Proton Diffusion of Doped Ni(OH)2

The Chronoamperometry of powder spherical Ni(OH) 2 microelectrode was used to study the proton diffusion coefficients of Ni(OH) 2. The proton diffusion coeefficients and the apparent diffusion active energy in anode and cathode processes at different temperature were obtained. Compared with pure Ni(OH) 2, the apparent diffusion active energy( E a) of Ni(OH) 2 doped with Co and Co+Zn was decreased and the diffusion constant( D o) was increased in the anode and the cathode processes, respectively, the effect of Co was greater. In contrast, for Ni(OH) 2 doped with Zn, its E a was increased and D o was decreased. Therefore, it was concluded that the reaction activity of Ni(OH) 2 electrode doped by Co was enhanced due to the reduction of proton diffusion resistance, while the reaction activity of electrode doped by Zn was weakened due to the increase of proton diffusion resistance.