Owing to the lack of an intrinsic driving force for two-dimensional (2D) anisotropic growth of non-layered inorganic complexes, spontaneous direct growth into a lamellar structure is considered to be an effective way to obtain ultrathin/atomically thick nanosheets. Here, we demonstrate a fast chemical synthesis, in which non-layered nickel boron oxide (Ni–B_i) in situ forms ultrathin 2D nanosheet arrays vertically aligned on both sides of graphene support, constituting a trilayered sandwich heterostructure. The realization of such an open framework heterostructure circumvents the aggregation issue and thus maximizes the exposure of the active sites of the nanosheets. In addition, the direct integration of the eletrochemically active material on conductive support ensures fast charge transport in the thickness dimension along with high structural integrity and durability. Proof-of-concept catalysis performance reveals exceptional photo/electro-catalytic reactivity and stability of the 2D-on-2D layered hybrid. This work highlights the capability and ease of fabricating ultrathin 2D heterostructures that are potentially useful for a wide range of environment-related applications.

中文翻译：

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垂直组装在石墨烯上的超薄氧化硼镍硼纳米片：用于增强光/电催化的新型混合二维材料

由于缺乏对非层状无机复合物的二维（2D）各向异性生长的内在驱动力，自发直接生长为层状结构被认为是获得超薄/原子厚纳米片的有效方法。在这里，我们展示了一种快速的化学合成方法，其中原位无层氧化硼镍（Ni–B _i）形成在石墨烯载体的两侧垂直排列的超薄二维纳米片阵列，构成三层夹心异质结构。这样的开放框架异质结构的实现避免了聚集问题，从而最大化了纳米片的活性位点的暴露。另外，电化学活性材料在导电载体上的直接结合确保了在厚度尺寸上的快速电荷传输以及高的结构完整性和耐久性。概念验证的催化性能显示了2D-on-2D层状杂化体的出色的光/电催化反应性和稳定性。这项工作强调了制造超薄2D异质结构的能力和简便性，这些异质结构对于广泛的与环境相关的应用很有用。