Zhang Lingjie, Cai Weiwei, Bao Ningzhong
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, Jiangsu, 210009, P. R. China.
Adv Mater. 2021 Jun;33(22):e2100745. doi: 10.1002/adma.202100745. Epub 2021 Apr 20.
High-entropy materials are new-generation electrocatalysts for water splitting due to their excellent reactivity and highly tailorable electrochemical properties. Herein, a powerful top-level design strategy is reported to guide and design advanced high-entropy electrocatalysts by establishing reaction models (e.g., reaction energy barrier, conductivity, adsorption geometries for intermediates, and rate-determining step) to predict performance with the help of density functional theory (DFT) calculations. Accordingly, novel high-entropy Co-Cu-Fe-Mo (oxy)hydroxide electrocatalysts are fabricated by a new low-temperature electrochemical reconstruction method and their oxygen evolution reaction (OER) properties are thoroughly characterized. These as-prepared quaternary metallic (oxy)hydroxides present much better OER performance than ternary Co-Cu-Mo (oxy)hydroxide, Co-Fe-Mo (oxy)hydroxide, and other counterparts, and are demonstrated with a low overpotential of 199 mV at a current density of 10 mA cm and a 48.8 mV dec Tafel slope in 1 m KOH and excellent stability without decay over 72 h. The performance enhancement mechanism is also unraveled by synchrotron radiation. The work verifies the usefulness of high-entropy design and the great synergistic effect on OER performance by the incorporation of four elements, and also provides a new method for the construction of advanced high-entropy materials for energy conversion and storage.
高熵材料因其优异的反应活性和高度可定制的电化学性能，成为新一代用于水分解的电催化剂。在此，本文报道了一种强大的顶层设计策略，通过建立反应模型（如反应能垒、电导率、中间体的吸附几何结构和速率决定步骤），借助密度泛函理论（DFT）计算来指导和设计先进的高熵电催化剂，从而预测其性能。相应地，通过一种新的低温电化学重构方法制备了新型高熵Co-Cu-Fe-Mo（氧）氢氧化物电催化剂，并对其析氧反应（OER）性能进行了全面表征。这些制备的四元金属（氧）氢氧化物表现出比三元Co-Cu-Mo（氧）氢氧化物、Co-Fe-Mo（氧）氢氧化物及其他同类材料更好的OER性能，在1 m KOH中，在电流密度为10 mA cm时过电位低至199 mV，塔菲尔斜率为48.8 mV dec，且具有优异的稳定性，在72 h内无衰减。同步辐射也揭示了性能增强的机制。这项工作验证了高熵设计的有效性以及通过引入四种元素对OER性能产生的巨大协同效应，同时也为构建用于能量转换和存储的先进高熵材料提供了一种新方法。
