Study of amorphous Ni–S–Co alloy used as hydrogen evolution reaction cathode in alkaline medium.pdfVIP

Available online at International Journal of Hydrogen Energy 29 (2004) 243–248 /locate/ijhydene Study of amorphous Ni–S–Co alloy used as hydrogen evolution reaction cathode in alkaline mediu a ;∗ a a b a Qing Han , Kuiren Liu , Jianshe Chen , Xin Li , Xujun Wei a School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China b Beijing General Research Institute of Mining and Metallurgy, Beijing 100044, China Accepted 14 July 2003 Abstract Ni–S–Co alloy was obtained through electrodeposition in a modied Watts bath by adding thiourea (TU) and CoCl2 into the bath. The structure and morphology were determined by XRD and SEM respectively. The contents of S and Co were measured by EPMA correspondingly. The electrochemical properties, including the hydrogen evolution overvoltages (h.o.v.), the Tafel slope b and the exchange current density i0 of amorphous Ni–S–Co cathode were measured. The HER mechanis and the steady-state behavior of amorphous Ni–S–Co alloy in alkaline media were also investigated. The results indicate that the structure of Ni–S–Co alloy obtained is amorphous and it shows much higher electrochemical activity than other electrodes including amorphous Ni–S and Ni–S(La) electrodes partially due to the higher sulfur content in such electrode. The HER mechanis mis 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. ? 2003 I