Noble-Metal High-Entropy-Alloy Nanoparticles: Atomic-Level Insight into the Electronic Structure
Noble-Metal High-Entropy-Alloy Nanoparticles: Atomic-Level Insight into the Electronic Structure
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DOI：
10.1021/jacs.1c13616
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发表时间：
2022-03-02
影响因子：
15
通讯作者：
Kitagawa, Hiroshi
中科院分区：
文献类型：
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作者：
Wu, Dongshuang;Kusada, Kohei;Kitagawa, Hiroshi
高熵合金纳米粒子(HEA NPs)的组成空间极大地扩展了材料库的多样性。HEA NPs中的每个原子都有不同的元素配位环境，这需要在原子水平上了解局部电子结构。然而，这种结构还没有从实验或理论上得到揭示。我们首次合成了全部八种贵金属族元素组成的HEA纳米粒子(NM-HEA)。通过硬X射线光电子能谱和密度泛函理论的NP模型计算揭示了它们的电子结构。与单金属纳米粒子相比，NM-HEA纳米粒子的能级简并程度较低，这是HEA纳米粒子的一个共同特征。首次揭示了每个表面原子的局域态密度。在HEA纳米粒子中，相同组成元素的一些原子具有不同的LDOS谱，而其他元素的原子具有相似的LDOS谱。换句话说，HEA中的一个原子失去了它的元素身份，通过调整相邻的原子，有可能创造出理想的LDOS。通过有监督学习，揭示了电子结构变化的趋势。NM-HEA纳米粒子的析氢反应本征活性是工业铂/碳的10.8倍，是目前最好的催化剂之一。
The compositional space of high-entropy-alloy nanoparticles (HEA NPs) significantly expands the diversity of the materials library. Every atom in HEA NPs has a different elemental coordination environment, which requires knowledge of the local electronic structure at an atomic level. However, such structure has not been disclosed experimentally or theoretically. We synthesized HEA NPs composed of all eight noble-metal-group elements (NM-HEA) for the first time. Their electronic structure was revealed by hard X-ray photoelectron spectroscopy and density function theory calculations with NP models. The NM-HEA NPs have a lower degeneracy in energy level compared with the monometallic NPs, which is a common feature of HEA NPs. The local density of states (LDOS) of every surface atom was first revealed. Some atoms of the same constituent element in HEA NPs have different LDOS profiles, whereas atoms of other elements have similar LDOS profiles. In other words, one atom in HEA loses its elemental identity and it may be possible to create an ideal LDOS by adjusting the neighboring atoms. The tendency of the electronic structure change was shown by supervised learning. The NM-HEA NPs showed 10.8-times higher intrinsic activity for hydrogen evolution reaction than commercial Pt/C, which is one of the best catalysts.