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Transition from Diffusion‐Controlled Intercalation into Extrinsically Pseudocapacitive Charge Storage of MoS2 by Nanoscale Heterostructuring |
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| Authors: | Qasim Mahmood Sul Ki Park Kideok D. Kwon Sung‐Jin Chang Jin‐Yong Hong Guozhen Shen Young Mee Jung Tae Jung Park Sung Woon Khang Woo Sik Kim Jing Kong Ho Seok Park |
| Affiliation: | 1. Department of Chemical Engineering, College of Engineering, Kyung Hee University, Yongin‐si, Gyeonggi‐do, Republic of Korea;2. School of Chemical Engineering, Sungkyunkwan University (SKKU), Jangan‐gu, Suwon, Republic of Korea;3. Department of Geology, Kangwon National University, Chuncheon‐si, Chuncheon, Republic of Korea;4. Department of Chemistry, Chung‐Ang University, Dongjak‐gu, Seoul, Republic of Korea;5. Department of Electrical Engineering and Computer Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA;6. Institute of Semiconductors, Chinese Academy of Sciences, Beijing, P. R. China;7. Department of Chemistry and Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon‐si, Chuncheon, Republic of Korea |
| Abstract: | 2D nanomaterials have been found to show surface‐dominant phenomena and understanding this behavior is crucial for establishing a relationship between a material's structure and its properties. Here, the transition of molybdenum disulfide (MoS2) from a diffusion‐controlled intercalation to an emergent surface redox capacitive behavior is demonstrated. The ultrafast pseudocapacitive behavior of MoS2 becomes more prominent when the layered MoS2 is downscaled into nanometric sheets and hybridized with reduced graphene oxide (RGO). This extrinsic behavior of the 2D hybrid is promoted by the fast Faradaic charge‐transfer kinetics at the interface. The heterostructure of the 2D hybrid, as observed via high‐angle annular dark field–scanning transmission electron microscopy and Raman mapping, with a 1T MoS2 phase at the interface and a 2H phase in the bulk is associated with the synergizing capacitive performance. This 1T phase is stabilized by the interactions with the RGO. These results provide fundamental insights into the surface effects of 2D hetero‐nanosheets on emergent electrochemical properties. |
| Keywords: | batteries charge transport energy storage mechanism hybrid materials pseudocapacitor 2D materials |