Si Jingjing, Yu Jinqiu, Lan Haihui, Niu Lixin, Luo Jingrui, Yu Yantao, Li Linyang, Ding Yu, Zeng Mengqi, Fu Lei
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, China.
J Am Chem Soc. 2023 Jan 27. doi: 10.1021/jacs.2c11139.
Two-dimensional (2D) transition-metal borides (TMBs) are especially expected to exhibit excellent performance in various fields among electricity, superconductivity, magnetism, mechanics, biotechnology, battery, and catalysis. However, the synthesis of ultrathin TMB single crystals with ultrahigh phase purity was deemed extremely challenging and has not been realized till date. That is because TMBs have the most kinds of crystal structures among inorganic compounds, which possess generous phase structures with similar formation energies compared with other transition-metal compounds, attributing to the metalloid and electron-deficient characteristics of boron. Herein, for the first time, we demonstrate a chemical potential-modulated strategy to realize the precise synthesis of various ultrahigh-phase-purity (approximately 100%) ultrathin TMB single crystals, and the precision in the phase formation energy can reach as low as 0.01 eV per atom. The ultrathin MoB single crystals exhibit an ultrahigh Young's modulus of 517 GPa compared to other 2D materials. Our work establishes a chemical potential-modulated strategy to synthesize ultrathin single crystals with ultrahigh phase purity, especially those with similar formation energies, and undoubtedly provides excellent platforms for their extensive research and applications.
二维（2D）过渡金属硼化物（TMBs）尤其有望在电学、超导、磁性、力学、生物技术、电池和催化等各个领域展现出优异性能。然而，合成具有超高相纯度的超薄TMB单晶被认为极具挑战性，迄今为止尚未实现。这是因为TMBs在无机化合物中具有最多的晶体结构类型，与其他过渡金属化合物相比，它们具有大量具有相似形成能的相结构，这归因于硼的类金属和缺电子特性。在此，我们首次展示了一种化学势调制策略，以实现各种超高相纯度（约100%）超薄TMB单晶的精确合成，并且相形成能的精度可低至每原子0.01 eV。与其他二维材料相比，超薄MoB单晶表现出517 GPa的超高杨氏模量。我们的工作建立了一种化学势调制策略来合成具有超高相纯度的超薄单晶，特别是那些具有相似形成能的单晶，无疑为它们的广泛研究和应用提供了优异的平台。
