Zhou Tianzhu, Ni Hong, Wang Yanlei, Wu Chao, Zhang Hao, Zhang Jianqi, Tomsia Antoni P, Jiang Lei, Cheng Qunfeng
Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, People's Republic of China.
School of Transportation Science and Engineering, Beihang University, Beijing 100191, People's Republic of China.
Proc Natl Acad Sci U S A. 2020 Apr 21;117(16):8727-8735. doi: 10.1073/pnas.1916610117. Epub 2020 Apr 6.
Graphene-based films with high toughness have many promising applications, especially for flexible energy storage and portable electrical devices. Achieving such high-toughness films, however, remains a challenge. The conventional mechanisms for improving toughness are crack arrest or plastic deformation. Herein we demonstrate black phosphorus (BP) functionalized graphene films with record toughness by combining crack arrest and plastic deformation. The formation of covalent bonding P-O-C between BP and graphene oxide (GO) nanosheets not only reduces the voids of GO film but also improves the alignment degree of GO nanosheets, resulting in high compactness of the GO film. After further chemical reduction and π-π stacking interactions by conjugated molecules, the alignment degree of rGO nanosheets was further improved, and the voids in lamellar graphene film were also further reduced. Then, the compactness of the resultant graphene films and the alignment degree of reduced graphene oxide nanosheets are further improved. The toughness of the graphene film reaches as high as ∼51.8 MJ m, the highest recorded to date. In situ Raman spectra and molecular dynamics simulations reveal that the record toughness is due to synergistic interactions of lubrication of BP nanosheets, P-O-C covalent bonding, and π-π stacking interactions in the resultant graphene films. Our tough black phosphorus functionalized graphene films with high tensile strength and excellent conductivity also exhibit high ambient stability and electromagnetic shielding performance. Furthermore, a supercapacitor based on the tough films demonstrated high performance and remarkable flexibility.
具有高韧性的石墨烯基薄膜有许多前景广阔的应用，特别是在柔性储能和便携式电子设备方面。然而，实现这种高韧性薄膜仍然是一项挑战。传统的提高韧性的机制是裂纹止裂或塑性变形。在此，我们通过结合裂纹止裂和塑性变形，展示了具有创纪录韧性的黑磷（BP）功能化石墨烯薄膜。BP与氧化石墨烯（GO）纳米片之间形成的共价键P-O-C不仅减少了GO薄膜的孔隙，还提高了GO纳米片的排列程度，从而使GO薄膜具有高致密性。经过共轭分子的进一步化学还原和π-π堆积相互作用后，还原氧化石墨烯（rGO）纳米片的排列程度进一步提高，层状石墨烯薄膜中的孔隙也进一步减少。然后，所得石墨烯薄膜的致密性和还原氧化石墨烯纳米片的排列程度进一步提高。石墨烯薄膜的韧性高达约51.8 MJ m，是迄今为止记录的最高值。原位拉曼光谱和分子动力学模拟表明，创纪录的韧性归因于所得石墨烯薄膜中BP纳米片的润滑、P-O-C共价键和π-π堆积相互作用的协同作用。我们具有高拉伸强度和优异导电性的坚韧黑磷功能化石墨烯薄膜还表现出高环境稳定性和电磁屏蔽性能。此外，基于这种坚韧薄膜的超级电容器表现出高性能和出色的柔韧性。
