In Situ TEM Reveals Direct One-Step Reduction of van der Waals Crystal MoO3 to Mo

IF 9.1 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters Pub Date : 2025-09-04 DOI:10.1021/acs.nanolett.5c03929

Wei Tu, Fan Zhang, Xiankun Song, Lu Jin, An Bai, Zhen Zeng, Tianding Xu*, Xianhu Sun*, Yao Yang and Jianyu Huang*,

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Abstract

Molybdenum oxides (MOs) exhibit rich polymorphism and tunable properties, yet their phase transformation pathways are poorly understood. Here, we employ in situ environmental transmission electron microscopy (TEM) to reveal a direct reduction of MoO₃ to metallic Mo, bypassing known intermediate phases such as MoO₂ and Mo₄O₁₁. Surface nucleation begins at approximately 800 °C and is completed at 900 °C. Molecular dynamics (MD) and density functional theory (DFT) calculations attribute this unexpected transformation to the van der Waals (vdW) layered structure of MoO₃, which lowers both the oxygen binding energy and the Gibbs free energy (ΔG) for oxygen desorption under high-vacuum and high-temperature conditions. Preferential oxygen removal from the weakly bonded vdW layers facilitates a rapid reduction to the metallic phase. These findings uncover a nonclassical reduction mechanism and provide a pathway for the rational design of MOs with controllable phases and properties.

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原位透射电镜显示范德华晶体MoO3直接一步还原为Mo

钼氧化物（MOs）具有丰富的多态性和可调的性质，但其相变途径尚不清楚。在这里，我们使用原位环境透射电子显微镜（TEM）揭示了MoO3直接还原为金属Mo，绕过了已知的中间相，如MoO2和Mo4O11。表面成核开始于约800 °C，完成于900 °C。分子动力学（MD）和密度功能理论（DFT）计算将这种意想不到的转变归因于MoO3的范德华（vdW）层状结构，该结构降低了高真空和高温条件下氧解吸的氧结合能和吉布斯自由能（ΔG）。弱键合的vdW层优先脱氧有利于快速还原为金属相。这些发现揭示了一种非经典还原机制，为合理设计具有可控相和性能的MOs提供了途径。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Nano Letters 工程技术-材料科学：综合

CiteScore

16.80

自引率

2.80%

发文量

1182

审稿时长

1.4 months

期刊介绍： Nano Letters serves as a dynamic platform for promptly disseminating original results in fundamental, applied, and emerging research across all facets of nanoscience and nanotechnology. A pivotal criterion for inclusion within Nano Letters is the convergence of at least two different areas or disciplines, ensuring a rich interdisciplinary scope. The journal is dedicated to fostering exploration in diverse areas, including: - Experimental and theoretical findings on physical, chemical, and biological phenomena at the nanoscale - Synthesis, characterization, and processing of organic, inorganic, polymer, and hybrid nanomaterials through physical, chemical, and biological methodologies - Modeling and simulation of synthetic, assembly, and interaction processes - Realization of integrated nanostructures and nano-engineered devices exhibiting advanced performance - Applications of nanoscale materials in living and environmental systems Nano Letters is committed to advancing and showcasing groundbreaking research that intersects various domains, fostering innovation and collaboration in the ever-evolving field of nanoscience and nanotechnology.