Scalable Synthesis of 2D Si Nanosheets

5 years ago

Scalable Synthesis of 2D Si Nanosheets

Jialiang Lang, Shuai Zhang, Longhao Qi, Hui Wu, Binghui Ge, Hanxiao Su, Qunyang Li, Huajian Gao, Bin Ding, Xiaoyan Li

2D Si nanomaterials have attracted tremendous attention due to their novel properties and a wide range of potential applications from electronic devices to energy storage and conversion. However, high-quality and large-scale fabrication of 2D Si remains challenging. This study reports a room-temperature and one-step synthesis technique that leads to large-scale and low-cost production of Si nanosheets (SiNSs) with thickness ≈4 nm and lateral size of several micrometers, based on the intrinsic delithiation process of chemically leaching lithium from the Li13Si4 alloy. Together with experimental results, a combination of theoretical modeling and atomistic simulations indicates that the formation of single SiNS arises from spontaneous delamination of nanosheets from their substrate due to delithiation-induced mismatch. Subsequently, the synthesized Si nanosheets evolve from amorphous to nanocrystalline to crystalline structures during annealing at different temperatures. It is demonstrated that these SiNSs possess unique mechanical properties, in particular ultralow friction, in contrast to their bulk counterparts. A room-temperature and one-step synthesis of Si nanosheets (SiNSs) is demonstrated for the first time. Via the delithiation process of chemically leaching lithium from the Li13Si4 alloy, large-scale synthesis of SiNSs with thickness ≈4 nm and lateral size of several micrometers is achieved with low cost.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201701777