期刊论文

Liu Su-Qin

中文

无机化学学报

1001-4861

2009

25

3

417-421

10.3321/j.issn:1001-4861.2009.03.008

湖南省自然科学基金（No.JJ073021）项目资助；

本校为其他机构

采用循环伏安、极化曲线和交流阻抗技术研究了在0.8 mol·L~(-1)VOSO_4+3.0 mol·L~(-1)H2SO4中,Ⅴ(Ⅳ/Ⅴ)电对在碳纸电极上的反应机理及可能的速度控制步骤.研究结果表明:Ⅴ(Ⅳ/Ⅴ)电对在碳纸电极上的反应属准可逆过程,且氧化过程包含有后置化学转化步骤.计算得到VO2+的扩散系数为4.5×10~(-5)cm~2·s~(-1).理论计算得到了电化学步骤和后置化学转化过程分别为控制步骤时的Tafel斜率值为0.12和0.06,实验得到的Tafel斜率值为0.127,交换电流密度为6.7×10~(-4) mA·cm~(-2).表明电极氧化过程受电化学过程控制,不同极化电位下的交流阻抗图潜拟合结果表明,电化学反应阻抗值远大于其他阻抗值,说明电化...

The V(IV/V) reaction mechanism was investigated on a carbon paper(CP) electrode by means of cyclic voltammetry, polarization curve and impedance spectroscopies. Cyclic voltammetry analysis indicated that V(IV/V) redox reaction, at CP electrode was quasi-reversible. A certain chemical reaction step was suspected to follow the electron transfer step of this reaction. The diffusion coefficient for V(IV) was 4.5×10 -5cm 2 · 8 -1 and exchange current density was 6.7×10 -4 mA · cm -2. The Tafel slope value(0.127) obtained, from the polarization c...