Exfoliation of a non-van der Waals material from iron ore hematite
Exfoliation of a non-van der Waals material from iron ore hematite
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DOI：
10.1038/s41565-018-0134-y
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发表时间：
2018-07-01
影响因子：
38.3
通讯作者：
Ajayan, Pulickel M.
中科院分区：
文献类型：
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作者：
Balan, Aravind Puthirath;Radhakrishnan, Sruthi;Ajayan, Pulickel M.
随着研究最多的二维材料石墨烯的出现，许多无机类似物被合成出来，并被开发用于新的应用。已经使用了几种方法来获得大颗粒、高质量的材料。例如，自然产出的矿石是通过剥离获得高度有序和大颗粒原子层的最佳先驱物。在这里，我们展示了一种从天然铁矿石赤铁矿(α-Fe_2O_3)中通过液体剥离的方法分离出来的新的二维材料‘Hephene’。用透射电子显微镜证实了其二维形貌。磁性测量和密度泛函理论计算证实了氢原子中的铁磁有序，而母体则表现出反铁磁有序。当负载在二氧化钛纳米管阵列上时，稀表现出增强的可见光催化活性。我们的研究表明，尽管存在不利于电荷转移的能带排列，但光生电子可以从氢化氢转移到二氧化钛。
With the advent of graphene, the most studied of all two-dimensional materials, many inorganic analogues have been synthesized and are being exploited for novel applications. Several approaches have been used to obtain large-grain, high-quality materials. Naturally occurring ores, for example, are the best precursors for obtaining highly ordered and large-grain atomic layers by exfoliation. Here, we demonstrate a new two-dimensional material 'hematene' obtained from natural iron ore hematite (alpha-Fe2O3), which is isolated by means of liquid exfoliation. The two-dimensional morphology of hematene is confirmed by transmission electron microscopy. Magnetic measurements together with density functional theory calculations confirm the ferromagnetic order in hematene while its parent form exhibits antiferromagnetic order. When loaded on titania nanotube arrays, hematene exhibits enhanced visible light photocatalytic activity. Our study indicates that photogenerated electrons can be transferred from hematene to titania despite a band alignment unfavourable for charge transfer.