Wang Chunyang, Zhao Shen, Han Guoqiang, Bian Haowei, Zhao Xinrui, Wang Lina, Xie Guangwen
College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao, 266045, P. R. China.
Institute of Advanced Magnetic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, 310012, China.
Small Methods. 2024 Oct;8(10):e2301691. doi: 10.1002/smtd.202301691. Epub 2024 Feb 19.
Water electrolysis is considered the cleanest method for hydrogen production. However, the widespread popularization of water splitting is limited by the high cost and scarce resources of efficient platinum group metals. Hence, it is imperative to develop an economical and high-performance electrocatalyst to improve the efficiency of hydrogen evolution reaction (HER). In this study, a hierarchical porous sandwich structure is fabricated through dealloying FeCoNiCuAlMn high-entropy alloy (HEA). This free-standing electrocatalyst shows outstanding HER performance with a very small overpotential of 9.7 mV at 10 mA cm and a low Tafel slope of 56.9 mV dec in 1 M KOH solution, outperforming commercial Pt/C. Furthermore, this electrocatalytic system recorded excellent reaction stability over 100 h with a constant current density of 100 mA cm. The enhanced electrochemical activity in high-entropy alloys results from the cocktail effect, which is detected by density functional theory (DFT) calculation. Additionally, micron- and nano-sized pores formed during etching boost mass transfer, ensuring sustained electrocatalyst performance even at high current densities. This work provides a new insight for development in the commercial electrocatalysts for water splitting.
水电解被认为是制氢最清洁的方法。然而，高效铂族金属的高成本和稀缺资源限制了水分解的广泛普及。因此，开发一种经济高效的电催化剂以提高析氢反应（HER）的效率势在必行。在本研究中，通过脱合金化FeCoNiCuAlMn高熵合金（HEA）制备了一种分级多孔三明治结构。这种独立式电催化剂在1 M KOH溶液中表现出优异的HER性能，在10 mA cm时过电位非常小，仅为9.7 mV，塔菲尔斜率低至56.9 mV dec，优于商业Pt/C。此外，该电催化系统在100 mA cm的恒定电流密度下记录了超过100小时的优异反应稳定性。高熵合金中增强的电化学活性源于鸡尾酒效应，这是通过密度泛函理论（DFT）计算检测到的。此外，蚀刻过程中形成的微米和纳米级孔隙促进了传质，即使在高电流密度下也能确保电催化剂性能的持续稳定。这项工作为开发用于水分解的商业电催化剂提供了新的见解。
