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This content will become publicly available on May 11, 2018

Title: Triphasic 2D Materials by Vertically Stacking Laterally Heterostructured 2H-/1T'-MoS 2 on Graphene for Enhanced Photoresponse

Recently the applications of two-dimensional (2D) materials have been broadened by engineering their mechanical, electronic, and optical properties through either lateral or vertical hybridization. Along with this line, we report the successful design and fabrication of a novel triphasic 2D material by vertically stacking lateral 2H-/1T'-molybdenum disulfide (MoS 2) heterostructures on graphene with the assistance of supercritical carbon dioxide. This triphasic structure is experimentally shown to significantly enhance the photocurrent densities for hydrogen evolution reactions. First-principles theoretical analyses reveal that the improved photoresponse should be ascribed to the beneficial band alignments of the triphasic heterostructure. More specifically, electrons can efficiently hop to the 1T'-MoS 2 phase via the highly conductive graphene layer as a result of their strong vertical interfacial electronic coupling. Subsequently, the electrons acquired on the 1T'-MoS 2 phase are exploited to fill the photoholes on the photo-excited 2H-MoS 2 phase through the lateral heterojunction structure, thereby suppressing the recombination process of the photo-induced charge carriers on the 2H-MoS 2 phase. This novel triphasic concept promises to open a new avenue to widen the molecular design of 2D hybrid materials for photonics-based energy conversion applications.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4] ; ORCiD logo [5]
  1. Zhengzhou Univ. (China). College of Materials Science and Engineering
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS) and Computational Sciences and Engineering Division
  3. Shaanxi Normal Univ., Xi'an City (China). Key Lab. for Macromolecular Science of Shaanxi Province School of Chemistry and Chemical Engineering
  4. Griffith Univ., QLD (Australia). Griffith School of Environment, Centre for Clean Environment and Energy; Chinese Academy of Sciences (CAS), Hefei (China). Inst. of Solid State Physics, Centre for Environmental and Energy Nanomaterials
  5. Griffith Univ., QLD (Australia). Griffith School of Environment, Centre for Clean Environment and Energy
Publication Date:
Grant/Contract Number:
AC05-00OR22725; 51173170; 21101141
Type:
Accepted Manuscript
Journal Name:
Advanced Electronic Materials
Additional Journal Information:
Journal Volume: 3; Journal ID: ISSN 2199-160X
Publisher:
Wiley
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Science (SC); Australian Research Council (ARC); National Natural Science Foundation of China (NNSFC)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; triphasic two-dimensional heterostructures; lateral heterojunction; vertical stacking; photoresponses; hydrogen evolution reactions
OSTI Identifier:
1356943