Electrocatalysis, such as water electrolysis and fuel cells, is the leading candidate for achieving carbon neutrality. The metastable-phase two-dimensional (2D) oxides enhance catalytic performances in electrocatalysis due to the joint advantages of the 2D structure and metastable-phase, which are regarded as some of the most advanced electrocatalytic materials, although they are still at an early stage of development for such materials. Herein, we summarize the properties of metastable-phase 2D metal oxides based on their singular structures first. Thereafter, the structure analysis is reviewed in detail over some representative nanomaterials, especially for metastable-phase 2D metal oxides materials. Subsequently, we particularly emphasize the applications of the representative materials. Finally, we discuss the major challenges and new opportunities in the emerging field of metastable-phase 2D metal oxides. The work will not only provide a comprehensive understanding over metastable-phase 2D metal oxides in structure and performance but also supply the guidance on designing electrocatalysts with excellent performance.

中文翻译：

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用于先进电催化的亚稳相二维金属氧化物

电催化，例如水电解和燃料电池，是实现碳中和的主要候选技术。亚稳相二维（2D）氧化物由于二维结构和亚稳相的共同优势，增强了电催化催化性能，被认为是最先进的电催化材料，尽管它们仍处于早期阶段此类材料的开发。在这里，我们首先根据其奇异结构总结了亚稳相二维金属氧化物的性质。此后，详细回顾了一些代表性纳米材料的结构分析，特别是亚稳相二维金属氧化物材料。随后，我们特别强调了代表性材料的应用。最后，我们讨论了亚稳相二维金属氧化物新兴领域的主要挑战和新机遇。该工作不仅可以全面了解亚稳相二维金属氧化物的结构和性能，还可以为设计具有优异性能的电催化剂提供指导。