采用循环伏安法研究了Fe(Ⅲ)/Fe(Ⅱ)在[Bmim]BF4-FeCl3-H2O体系中的电化学行为。研究表明,在[Bmim]BF4—FeCl3-H2O体系中只观察到Fe(Ⅲ)/Fe(Ⅱ)的氧化还原反应,没有观察到Fe(Ⅱ)/Fe的氧化还原Fe(Ⅲ)/Fe(Ⅱ)的氧化还原反应是扩散控制的可逆过程。还原峰值电流随扫描速率增大而增大,并符合Randles—Sevcik方程。Fe(Ⅲ)在[Bmim]BF4-FeCl3-H2O体系中的扩散系数与温度的关系符合Arrhenius公式,其扩散活化能为41.432kJ/mol。
The electrochemical behaviors of Fe(Ⅲ)/Fe(Ⅱ) redox couple in [Bmim]BF4-FeCl3-H2O system were investigated by cyclic voltammetry. The Fe(Ⅲ)/Fe(Ⅱ) rather than Fe(Ⅱ)/Fe redox reaction was ohserved in [Bmim]BF4-FeCl3-H2O system. It was found that Fe(Ⅲ)/Fe(Ⅱ) redox reaction is a diffusioncontrolled reversible process. The reduction peak current is directly proportional to the square root of scanning rate, which can be described by Randles-Sevcik equation. The relationship between diffusion coefficient and temperature agrees well with the Arrhenius equation and the diffusion activation energy of Fe(Ⅲ) in [Bmim]BF4-FeCl3-H2O system is 41. 432 kJ/mol.