In Situ Thermolysis of a Ni Salt on Amorphous Carbon and Graphene Oxide Substrates
In Situ Thermolysis of a Ni Salt on Amorphous Carbon and Graphene Oxide Substrates
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DOI：
10.1002/adfm.202213747
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发表时间：
2023-04
影响因子：
19
通讯作者：
Mahmound Tamadoni Saray;Vitaliy Yurkiv;R. Shahbazian‐Yassar
中科院分区：
文献类型：
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作者：
Mahmound Tamadoni Saray;Vitaliy Yurkiv;R. Shahbazian‐Yassar
了解金属盐前驱体在碳结构上的热分解对金属修饰碳纳米材料的受控合成至关重要。本文利用原位透射电子显微镜研究了镍前驱体盐NiCl2·6H2O在非晶碳（a‐C）和氧化石墨烯（GO）衬底上的热裂解。NiCl2·6H2O在氧化石墨烯上的热分解发生在比在−C底物上更高的温度和更慢的动力学下。这与密度泛函理论计算的Cl2去除的高激活势垒、强Ni - GO相互作用、高密度氧官能团、缺陷和使用GO衬底的弱范德华效应有关。NiCl2·6H2O的热分解经过多步分解形成镍纳米颗粒，其大小和分布随衬底的不同而有显著差异。使用氧化石墨烯衬底可以使纳米颗粒的平均尺寸比- C衬底小500%，并且具有更高的热稳定性。镍纳米颗粒呈现fcc晶体结构，晶粒尺寸对晶体结构的稳定性没有影响。这些发现证明了碳衬底对碳-金属异质结构热分解过程中纳米颗粒的形成和生长的重要作用。这为设计稳定的、支持的催化剂和新的碳基传感器和过滤装置开辟了新的场所。
Understanding the thermal decomposition of metal salt precursors on carbon structures is essential for the controlled synthesis of metal‐decorated carbon nanomaterials. Here, the thermolysis of a Ni precursor salt, NiCl2·6H2O, on amorphous carbon (a‐C) and graphene oxide (GO) substrates is explored using in situ transmission electron microscopy. Thermal decomposition of NiCl2·6H2O on GO occurs at higher temperatures and slower kinetics than on a‐C substrate. This is correlated to a higher activation barrier for Cl2 removal calculated by the density functional theory, strong Ni‐GO interaction, high‐density oxygen functional groups, defects, and weak van der Waals using GO substrate. The thermolysis of NiCl2·6H2O proceeds via multistep decomposition stages into the formation of Ni nanoparticles with significant differences in their size and distribution depending on the substrate. Using GO substrates leads to nanoparticles with 500% smaller average sizes and higher thermal stability than a‐C substrate. Ni nanoparticles showcase the fcc crystal structure, and no size effect on the stability of the crystal structure is observed. These findings demonstrate the significant role of carbon substrate on nanoparticle formation and growth during the thermolysis of carbon–metal heterostructures. This opens new venues to engineer stable, supported catalysts and new carbon‐based sensors and filtering devices.