Engineering active sites of two-dimensional MoS2 nanosheets for improving hydrogen evolutionElectronic supplementary information (ESI) available: Details of Experimental section and electrochemical tests. See DOI: 10.1039/c6qi00334f

Generating more and fresh active sites is challenging for 2D MoS 2 . Herein, the old S edges were peeled off and the inner S atoms were disclosed as under-coordinated atoms. This realized more and freshly active sites being exposed that facilitate adsorption of intermediates and lead to dramatic enhancements in its HER activity in both acid and alkaline electrolytes. S edges were peeled off to disclose inner S as new under-coordinated atoms, which exposed more fresh active sites.