用电沉积方法制备非晶态Ni-S-Co合金镀层, 研究了镀层的电化学性能. 结果表明,与非晶态Ni--S合金相比, Co的引入可提高镀层中S的含量.在析氢反应中非晶态Ni--S--Co合金电极具有很高的电化学活性,电流密度为150 mA×cm-2时其析氢过电位仅为70 mV,比非晶态Ni-S合金低20 mV.在长时间电解过程中S发生溶出反应有助于提高电极的表面粗糙程度, 是提高电极析氢活性的重要原因之一. 在析氢过程中,非晶态Ni--S--Co合金电极吸附大量的H原子, 使反应的活化能降低,这是其析氢活性高的主要原因. 非晶态Ni--S--Co合金镀层的析氢机理为电化学脱附机理,即一快速的Volmer反应(电化学步骤)和一较慢的Heyrovsky反应(电化学脱附步骤).
Ni-S-Co alloy was obtained through electrodeposition in a modified Watts bath by adding thiourea (TU) and CoCl2 into the bath. The amorphous structure was determined by XRD. The contents of S and Co were measured by EPMA. The electrochemical parameters such as the hydrogen evolution reaction overvoltage (η) being 70 mV at 150 mA•cm-2, the Tafel slope b, the exchange current density i0 and the activation energies ΔH* were obtained. Much higher electrochemical activity of amorphous Ni-S-Co cathode than other electrodes including amorphous Ni-S electrode is determined. The results that the HER mechanism is a fast Volmer reaction following a slow Heyrovsky reaction and the high electrocatalytic HER property is mainly due to the large amount of adsorbed H atoms is obtained by the steady-state behaviors of amorphous Ni-S-Co alloy in alkaline media at various pH and the cyclic voltammetric curves.
参考文献
| [1] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%