▎ 摘　　要

The edge and corner atoms of 2D transition metal dichalcogenides (TMDCs) are the main electrocatalytically active sites for electrochemical reaction. Here, we demonstrate an approach to generate abundant edge/corner atoms in molybdenum diselenide (MoSe2) nanocrystals supported by nitrogen-doped graphene (NG) which consequently leads to significantly enhanced hydrogen evolution reaction (HER) activity. These structures were fabricated by firstly absorbing the Mo-containing precursor within polymer-functionalized graphene oxide, then selenized to obtain MoSe2 nanocrystals on the surface, and finally H-2 etching was performed to form perforated structures. The use of a functional polymer as an absorption matrix efficiently mitigates aggregation which allows us to obtain MoSe2 single-crystals of similar to 150 nm in lateral dimension, while maintaining high MoSe2 loading. We observed a remarkably enhanced electrocatalytic activity resulting from a significantly increased abundance of edge/corner atoms in hydrogen evolution measurements. Specifically, with this perforated MoSe2/NGmodified cathode, current densities of -1 and -10 mA cm(-2) were realized with the overpotentials of only 30 and 106 mV, along with a small Tafel slope of 57 mV dec(-1) and large exchange current density of 127.4 mu A cm(-2) in 0.5 M H2SO4. Such an efficient strategy also opens doors for the unparalleled design and fabrication of TMDC-based nanocomposites for electrochemical applications.