With the support of the National Natural Science Foundation of China and the Ministry of Science and Technology's major research project and other projects, Li Yadong's research group at Tsinghua University successfully prepared monoatomic nanometer rhodium sheets for the first time. Since the discovery of graphene, single-layer materials containing delocalized large P bonds have received much attention from the scientific community, mainly focusing on material systems with layered structures. So far, the metal structure of the monoatomic layer with delocalized electronic properties has not been reported. The main reason is that the metal bonds are non-directional and tend to form a three-dimensional close-packed structure. Duan Haohong, PhD student of Li Yadong's research group at Tsinghua University, used the weak ligand polyvinylpyrrolidone (PVP) stabilized formaldehyde to reduce rhodium metal, and successfully prepared the first case of single-atom-thickness nanometer rhodium metal sheet. Confirmed this novel monoatomic metal structure. Theoretical research found that there is a new type of delocalized large chemical bond in the monoatomic rhodium sheet, which helps to stabilize its monolayer metal structure. The research progress is of great significance to further promote the research of chemical bonding theory of metal nanometers and clusters, and enrich the development of heavy metal elements, and provides important inspiration for the exploration of the structure and performance of metal atom monolayers. Chongqing Sungrace International Trading Co.,Ltd , https://www.sungracetrading.com