A model for understanding the temperature change of an alternate hot and cold micro-band graphite electrode

作者：Yang, Sen; Huang, Zong-Xiong; Hou, Xiao-Heng; Cheng, Fang-Fang; Wu, Shao-Hua; Sun, Jian-Jun^*

来源：Electrochemistry Communications, 2016, 68: 71-75.

DOI：10.1016/j.elecom.2016.05.007

• Model
• Alternate hot and cold micro-band graphite electrode
• Supercooled temperature
• Ferricyanide
• Diffusion coefficient
• Activation energy

A model is established for understanding the temperature change of an alternate hot and cold micro-band graphite electrode. It consists of two symmetrically placed thermoelectric coolers with an embedded graphite sheet as interlayer. By measuring the open circuit behaviors of a standard redox couple, the electrode surface temperature can be detected. And the electrode surface temperature can be regulated from 40 degrees C to -10 degrees C in aqueous solution without freezing. The model is described as Qh = gamma h Delta T, Qc = gamma(c) Delta T, where the temperature change (Delta T) of electrode surface is assumed to be proportional to power of heating (Q(h)) or cooling (Q(c)). In addition, the diffusion activation energy of ferricyanide ion is firstly achieved by extending the temperature range from above zero degree down to the supercooled temperature (-10 degrees C) with this specially designed electrode. Diffusion coefficient of ferricyanide ion is ca. 0.22 x 10(-5) cm(-2) s(-1) at -10 degrees C, and activation energy is 23.2 kJ mol(-1). The experimental data are consistent with data obtained by Stokes-Einstein equation for the determination of diffusion coefficient and activation energy.

• 单位
  福州大学