Strong, Ductile, and Tough Nanocrystal-Assembled Freestanding Gold Nanosheets
Qing Yu, Jingyang Zhang, Jia Li, Tianyu Wang, Minhyuk Park, Quanfeng He, Zhibo Zhang, Tao Liang, Xue Ding, Yang Yang Li, Qing Wang, Qiaoshi Zeng, Yong Yang
Abstract
The structural and mechanical properties of low-dimensional nanostructured metals have been attracting tremendous interest in the fast-growing fields of nanosciences and nanotechnologies. However, it still remains a challenge today to develop strong yet ductile low-dimensional metals that can support the further development of nanodevices. Here, through the polymer-assisted assembly of gold nanocrystals, we successfully fabricated the freestanding, ultrathin gold nanomaterial. Unlike conventional bulk gold or other low-dimensional gold nanostructures (i.e., nanowires and nanosheets), these gold nanosheets are composed of highly distorted gold nanocrystals that are 3–5 nm in size, which are joined together through nanosized amorphous carbon interphases. As a result, the gold nanosheets exhibit superb strength (up to 1.2 GPa), excellent ductility (>50%), and superior fracture toughness (>100 J/m2), outperforming various gold nanostructures hitherto reported.