电沉积Ni-S-Co/ZrO_2复合电极及其催化析氢性能

Electrodeposition of Ni-S-Co/ZrO_2 Composite Electrode and Its High HER Activity in Alkaline Solution

在镀液中悬浮粒径为200～400 nm的ZrO2固体颗粒,以电沉积方法制备了Ni-S-Co/ZrO2复合电极。XRD和SEM测试结果表明,沉积层由非晶态的Ni、Co、S和单斜晶型的ZrO2粒子组成。镀层表面呈团粒状结构,无裂隙,与基体结合牢固。电化学测试结果表明,25℃时,Ni-S-Co/ZrO2复合电极在质量分数28%NaOH水溶液中,在电流密度100 mA/cm2下的超电势为145 mV,与未复合纳米ZrO2粒子的Ni-S-Co电极相比降低了50 mV。表明超细ZrO2的掺入有效提高了电极对析氢反应的催化效果。实验表明,沉积的最佳电流密度为70 mA/cm2,最适宜的ZrO2用量为15 g/L,采用Ni-S-Co作为过渡层可以显著改善复合镀层与基体的结合。

A novel Ni-S-Co/ZrO2 composite electrode was prepared by electrodeposition with ZrO2 particles of 200 - 400 nm in diameter dispersed in the bath. The XRD results suggest that the Ni-S-Co/ ZrO2 coating is composed of amorphous Ni, Co, S and crystalline monoclinie ZrO2 particles. The SEM images show that the coating is composed of granules with porous surface and ca. 50μm in diameter, providing high specific area. The coating is homogeneous and tightly combines with the Ni substrate with a Ni-S-Co interconnecting layer. Electrochemical tests show that the overpotential for hydrogen evolution reaction（HER） of the Ni-S-Co/ZrO2 composite electrode is 145 mV at a current density of 100 mA/cm^2 in mass fraction 28% NaOH solution at 25 ℃ ,which is 50 mV lower than that of the Ni- S-Co electrode. The incorporation of ultrafine ZrO2 particles into the Ni-S-Co alloy coating effectively improves the electrocatalytie activity of the Ni-S-Co electrode for hydrogen evolution reaction. The optimal conditions for electrodeposition of the Ni-S-Co/ZrO2 composite electrode are studied as well.