Topochemical Deintercalation of Li from Layered LiNiB: toward 2D MBene
Topochemical Deintercalation of Li from Layered LiNiB: toward 2D MBene
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DOI：
10.1021/jacs.0c11397
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发表时间：
2021-03-15
影响因子：
15
通讯作者：
Zaikina, Julia, V
中科院分区：
文献类型：
--
作者：
Bhaskar, Gourab;Gvozdetskyi, Volodymyr;Zaikina, Julia, V
二维（2D）硼化物，MBenes的追求，已被证明是具有挑战性的，而不是因为缺乏一个合适的前体倾向于脱嵌。在这里，我们研究了室温下锂从LiNiB化合物的层状多晶型物中的局部化学脱嵌，其中大量的Li存储在[NiB]层之间（33 at. % Li）。Li的脱嵌导致具有独特晶体结构的新型亚稳硼化物（Li类似于0.5NiB）。通过在环境条件下将母相暴露于空气、水或稀HCl中来实现Li的部分去除。利用扫描透射电子显微镜和固体Li-7和B-1（1）NMR谱，结合X射线对分布函数（PDF）分析和密度泛函（DFT）计算，研究了Li类似于0.5Ni B的新结构及其脱嵌机理.我们已经表明，Li的脱嵌通过“拉链锁”机制进行，导致单层[NiB]层缩合成通过共价键结合的双层或三层，导致具有Li[NiB]（2）和Li[NiB]（3）组成的结构片段。Li的晶体结构类似于0.5NiB，最好描述为有序的单层[NiB]，双层[NiB]（2）或三层[NiB]（3）与单层Li交替生长;这解释了其结构的复杂性。双或三[NiB]层的形成诱导的磁性行为的变化，从温度无关的顺磁体在母体LiNiB化合物的自旋玻璃化的脱嵌锂类似于0.5NiB对应物。LiNiB化合物展示了获得大量独特材料的潜力，包括2D MBenes（NiB）。
The pursuit of two-dimensional (2D) borides, MBenes, has proven to be challenging, not the least because of the lack of a suitable precursor prone to the deintercalation. Here, we studied room-temperature topochemical deintercalation of lithium from the layered polymorphs of the LiNiB compound with a considerable amount of Li stored in between [NiB] layers (33 at. % Li). Deintercalation of Li leads to novel metastable borides (Li similar to 0.5NiB) with unique crystal structures. Partial removal of Li is accomplished by exposing the parent phases to air, water, or dilute HCl under ambient conditions. Scanning transmission electron microscopy and solid-state Li-7 and B-1(1) NMR spectroscopy, combined with X-ray pair distribution function (PDF) analysis and DFT calculations, were utilized to elucidate the novel structures of (Li similar to 0.5NiB) and the mechanism of Li-deintercalation. We have shown that the deintercalation of Li proceeds via a "zip-lock" mechanism, leading to the condensation of single [NiB] layers into double or triple layers bound via covalent bonds, resulting in structural fragments with Li[NiB](2) and Li[NiB](3) compositions. The crystal structure of Li similar to 0.5NiB is best described as an intergrowth of the ordered single [NiB], double [NiB](2), or triple [NiB](3) layers alternating with single Li layers; this explains its structural complexity. The formation of double or triple [NiB] layers induces a change in the magnetic behavior from temperature-independent paramagnets in the parent LiNiB compounds to the spin-glassiness in the deintercalated Li similar to 0.5NiB counterparts. LiNiB compounds showcase the potential to access a plethora of unique materials, including 2D MBenes (NiB).