1 Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece. [email protected][email protected].
Chlorosulfonic acid assisted the exfoliation of MoS2 and WS2 resulting in retaining their semiconducting 2H-phase, sharply contrasting the semiconducting-to-metallic phase-transition observed with the currently available exfoliation techniques.