Gold-assisted exfoliation has emerged as an effective method for producing large-area monolayers of two-dimensional materials, yet its underlying mechanism remains poorly understood. While other metals also hold promise for facilitating large-area exfoliation, their practical application is hindered by oxidation in air. To address this, we fabricate heterostructures of monolayer MoS2 with polycrystalline gold, silver, copper, palladium, cobalt, and nickel via direct mechanical exfoliation of bulk molybdenite under controlled atmospheric conditions. Our photoemission spectroscopy, vibrational spectroscopy, and density functional theory results reveal the metal-dependent modification of monolayer MoS2. We identify the hybridization directionality and, in particular, the asymmetry between the bottom and top sulfur atoms as previously overlooked key factors in weakening the MoS2-MoS2 van der Waals interaction, ultimately enabling selective monolayer exfoliation.

Department of Biological Physics Eötvös Loránd University Pázmány Péter sétány 1 A Budapest 1117 Hungary

Department of Physics and Astronomy University of Manchester Oxford Road Manchester M13 9PL United Kingdom

Faculty of Chemical Engineering University of Chemistry and Technology Prague Technická 5 166 28 Prague 6 Czech Republic

Hartree Centre STFC Daresbury Laboratory Daresbury WA4 4AD United Kingdom

Institute of Electronic Packaging Technology Technische Universität Dresden 01062 Dresden Germany

Institute of Ion Beam Physics and Materials Research Helmholtz Zentrum Dresden Rossendorf Bautzner Landstrasse 400 01328 Dresden Germany

Institute of Physics CAS Na Slovance 1999 2 182 21 Prague 8 Czech Republic

J Heyrovský Institute of Physical Chemistry Czech Academy of Sciences Dolejškova 2155 3 182 23 Prague 8 Czech Republic

Technische Universität Dresden 01069 Dresden Germany

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