在室温下通过热处理的石墨烯氧化物稳定
Artur Khannanov1, Airat Kiiamov1,2, Alina Valimukhametova1
1Laboratory for Advanced Carbon Nanomaterials , Kazan Federal University , Kazan 420008 , Russian Federation.
Journal of the American Chemical Society
|July 10, 2018
概括
研究人员在室温下发现了稳定的面中心立方体 (FCC) 铁纳米粒子,这是以前认为不可能的. 这些在石墨烯上稳定的奥氏体纳米粒子在能量储存和催化中具有潜在的应用.
科学领域:
- 材料科学
- 纳米技术
- 固态物理
背景情况:
- 在像石墨烯这样的表面上稳定纳米粒子对于电荷储存设备和催化剂的应用至关重要.
- 铁纳米粒子对这些应用具有吸引力,但它们的相稳定性是一个关键挑战.
- 已知面中心立方 (FCC) 马铁相仅存在于高温 (917°C以上).
研究的目的:
- 描述以前假定不存在的面中心立方 (FCC) 铁纳米粒子阶段的发现和特征.
- 在纳米粒子中研究这种马铁相的室温稳定性.
- 探索这些纳米粒子在碳材料上的稳定机制.
主要方法:
- 使用X射线衍射 (XRD) 来确定铁纳米颗粒的晶体结构.
- 使用Mössbauer光谱来确认铁的相位和电子状态.
- 使用受控合成生产具有特定直径和碳含量的纳米粒子.
主要成果:
- 这项研究成功地在室温下合成并识别了面中心立方体 (FCC) 铁纳米粒子.
- 这些含有0.60%至0.93%碳的奥氏体纳米粒子表现出意想不到的稳定性.
- 通过表面Fe/C固体溶液和几层石墨烯外稳定了直径从30nm到200nm的纳米粒子.
结论:
- 这项研究证明了纳米粒子中的马铁 (FCC) 阶段的室温稳定性,挑战了以前的热力学理解.
- 使用表面Fe/C固体溶液和石墨烯外的稳定机制是这种现象的关键.
- 这些发现为在各种技术应用中利用稳定的FCC铁纳米粒子开辟了新的途径,包括储能和催化.
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