Li Junming, Li Jun, Ren Jun, Hong Hong, Liu Dongxue, Liu Lizhe, Wang Dunhui
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, School of Physics, Nanjing University, Nanjing, 210093, People's Republic of China.
Hangzhou Dianzi University, Hangzhou, 310018, People's Republic of China.
Nanomicro Lett. 2022 Jul 22;14(1):148. doi: 10.1007/s40820-022-00889-3.
A novel physical approach is proposed to enhance the electrocatalytic performance by electric field. Under the action of electric field, some stable conductive filaments consisting of oxygen vacancies are formed in the Ni/CoO film, which remarkably reduces the system resistivity. The electric-field-treated Ni/CoO material exhibits significantly superior activity and stability as a bifunctional electrocatalyst for overall water splitting, and its performance exceeds the state-of-the-art electrocatalysts.
Rational design of bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with excellent activity and stability is of great significance, since overall water splitting is a promising technology for sustainable conversion of clean energy. However, most electrocatalysts do not simultaneously possess optimal HER/OER activities and their electrical conductivities are intrinsically low, which limit the development of overall water splitting. In this paper, a strategy of electric field treatment is proposed and applied to Ni/CoO film to develop a novel bifunctional electrocatalyst. After treated by electric field, the conductive channels consisting of oxygen vacancies are formed in the CoO film, which remarkably reduces the resistance of the system by almost 2 × 10 times. Meanwhile, the surface Ni metal electrode is partially oxidized to nickel oxide, which enhances the catalytic activity. The electric-field-treated Ni/CoO material exhibits super outstanding performance of HER, OER, and overall water splitting, and the catalytic activity is significantly superior to the state-of-the-art noble metal catalysts (Pt/C, RuO, and RuO ǁ Pt/C couple). This work provides an effective and feasible method for the development of novel and efficient bifunctional electrocatalyst, which is also promising for wide use in the field of catalysis. [Image: see text]
The online version contains supplementary material available at 10.1007/s40820-022-00889-3.
提出了一种通过电场增强电催化性能的新型物理方法。在电场作用下，Ni/CoO薄膜中形成了一些由氧空位组成的稳定导电细丝，这显著降低了系统电阻。经电场处理的Ni/CoO材料作为用于全水分解的双功能电催化剂表现出明显优异的活性和稳定性，其性能超过了现有最先进的电催化剂。
合理设计具有优异活性和稳定性的用于析氧反应（OER）和析氢反应（HER）的双功能电催化剂具有重要意义，因为全水分解是一种很有前景的清洁能源可持续转换技术。然而，大多数电催化剂不能同时具备最佳的HER/OER活性，并且它们的本征电导率较低，这限制了全水分解的发展。本文提出了一种电场处理策略并将其应用于Ni/CoO薄膜以开发一种新型双功能电催化剂。经电场处理后，CoO薄膜中形成了由氧空位组成的导电通道，这使系统电阻显著降低了近2×10倍。同时，表面的Ni金属电极部分氧化为氧化镍，这增强了催化活性。经电场处理的Ni/CoO材料在HER、OER和全水分解方面表现出极其优异的性能，并且催化活性明显优于现有最先进的贵金属催化剂（Pt/C、RuO₂和RuO₂||Pt/C偶联物）。这项工作为开发新型高效双功能电催化剂提供了一种有效且可行的方法，在催化领域也具有广泛应用前景。[图片：见正文]
在线版本包含可在10.1007/s40820-022-00889-3获取的补充材料。
