High-quality single-layer nanosheets of MS2 (M = Mo, Nb, Ta, Ti) directly exfoliated from AMS2 (A = Li, Na, K) crystals. Issue 24 (1st June 2017)

• Record Type: Journal Article
• Authors: Guo, Chenguang; Li, Hui; Zhao, Wei; Pan, Jie; Lin, Tianquan; Xu, Jijian; Chen, Mingwei; Huang, Fuqiang
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 24(2017)
• Page Start: 5977
• Page End: 5983
• Publication Date: 2017-06-01
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tc00838d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : A novel general strategy is developed to obtain high-quality transition metal dichalcogenide nanosheets with excellent transport properties. Abstract : Layered transition metal dichalcogenides (TMDs) such as MoS2 have attracted considerable interest as two-dimensional materials because of their unique physical and chemical properties. Single or few-layer TMD nanosheets can be achieved by conventional Li intercalation methods through organolithium chemistry or electrochemistry. However, these methods are hampered by the low yield, mixed phases and a lot of defects inside the nanosheets. Here we develop a novel general strategy to prepare single-layer TMD nanosheets by using AMS2 (A = Li, Na, K; M = Mo, Nb, Ta, Ti) crystals as ideal precursors. The crystal structure of these compounds ensures the robust S–M–S layers and fully filled alkali atoms between them, which lead to a high-yield production of high-quality single-layer nanosheets by following chemical exfoliation. Surprisingly, MoS2 nanosheets obtained by LiMoS2 crystals show a high-quality 1T′ phase, while the widely used n -butyl lithium method can only prepare phase-mixed (2H, 1T, 1T′) nanosheets with abundant defects. The as-prepared 1T′ MoS2 nanosheets exhibit a remarkable electrical conductivity (618 S cm −1 ), which is much higher than that of MoS2 nanosheets (35.4 S cm −1 ) obtained using the n -butyl lithium method, also the highest value in MoS2 related materials and superior to the best value of the reported 2D films of graphene (550 S cm −1 ).