Metallene: Ångström‐Scale 2D Metals

作者：Fengzhu Ren, Zhaoyang Han, Lingfeng Zhu, Zhihao Lei, Guozheng Shi, Zhixuan Li, Chun‐Ho Lin, Long Hu, Hui Li, Xinwei Guan, Baohua Jia, Prashant Kumar, Tianyi Ma · 发表于：Advanced Materials · 年份：2025 · DOI：10.1002/adma.202512683 · 被引用次数：12 · 研究领域：Graphene research and applications、2D Materials and Applications、Electronic and Structural Properties of Oxides

Atomically thin 2D metals, also termed metallenes, constitute a distinctive class of 2D materials in which metallic bonding is preserved at the ångström scale. Quantum confinement imparts ultrahigh carrier mobility, tunable plasmonic resonances, and exposed surfaces composed of low-coordination active sites. Although "2D metals" have historically encompassed various metallic nanostructures, recent breakthroughs have enabled the isolation of structurally well-defined metallenes with ambient stability and quantum-confined properties not observed in their bulk counterparts. This review provides a comprehensive overview of metallene research, focusing on their synthetic chemistry, low-dimensional metrics, and structure-function relationships. This unified framework provides cross-disciplinary insights for rational design in catalysis, plasmonics, electronics, and biomedical applications. Rigorous criteria are first established to distinguish true monolayer metals from quasi-2D nanosheets, emphasizing bonding anisotropy, lattice continuity, and spectroscopic fingerprints. State-of-the-art fabrication strategies are then benchmarked for scalability and technology readiness. Next, the engineering toolbox, including doping, hierarchical hetero-structuring, and defect/phase/strain modulation, is surveyed, which tailors these intrinsic traits and translates them into record performances across diverse applications. Finally, outstanding challenges, including thermodynamic metastability,...