掺杂Ni(OH)_2的质子扩散系数  

The Proton Diffusion Coefficient of Doped Ni(OH)_2

作　　者：刘建华[1] 杨敬武[1] 唐致远[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《应用化学》2000年第4期387-391,共5页Chinese Journal of Applied Chemistry

基　　金：天津市科委攻关项目! (97310 3711)

摘　　要：利用粉末微电极恒电位阶跃法 ,研究了掺杂元素对球形 Ni(OH) 2 阳极过程和阴极过程质子扩散系数的影响 .结果表明 ,与纯 Ni(OH) 2 相比 ,掺 Co、Co+Zn、Ca后镍微电极的阳极过程质子扩散系数稍有增大 ,掺 Zn、Fe、Mg后则有所降低 ,而掺杂 Co、Ca后的阴极过程质子扩散系数增大约 1倍 ,掺杂 Fe、Mg后则减少约 3/4倍 ;掺 Cd对阳极和阴极过程的质子扩散系数影响均不大 .尽管掺杂元素对扩散层厚度的影响不大 ,但阴极过程扩散系数比阳极过程小约 2个数量级 ,将是影响阴、阳极电极电化学过程的重要因素 .The chronoamperometry was used to study the powdery microelectrode made of spherical Ni(OH) 2. The effects of doping elements on the proton diffusion coefficients D H were investigated for anode and cathode processes at 25 ℃. The results showed that in comparison with pure Ni(OH) 2 the anode process diffusion coefficients ( D 0) of Ni(OH) 2 doped with Co, Co+Zn and Ca were increased a little and those of doped with Zn, Fe and Mg decreased. In contrast, the cathode diffusion coefficients ( D R) of Ni(OH) 2 doped with Co and Ca were almost doubled and that doped with Fe and Mg were reduced to one fourth as compared with that of pure Ni(OH) 2. Doping of Cd only had a very small effect on the D H for both anode and cathode. It appeared that doping of Co, Ca tends to increase the anode proton diffusion velocity, while doping of Fe and Mg tends to decrease the cathode diffusion velocity. The D H of the anode process were found to the 2 orders of magnitude higher than that of the cathode process (10 -12 vs 10 -10 cm 2/s).

关 键 词：微电极 恒电位阶跃 质子扩散系数 氢氧化镍 

分 类 号：O646.5[理学—物理化学]