Oriented Stacking along Vertical (002) Planes of MoS2: A Novel Assembling Style to Enhance Activity for Hydrogen Evolution

Abstract The layered structures of MoS 2 tend to stack and aggregate and result in decreasing of rims and edges of MoS 2 nanosheets, which greatly limited the improvement of activity of MoS 2 as electrocatalysts for hydrogen evolution reaction (HER). Herein, owing to the inert nature of (002) basal plane of MoS 2 for HER, we propose that oriented stacking along vertical (002) plane can form nanocolumn structure, which may expose an increased number of the active sites per mass and accelerate charge transfer rate for HER. The electrochemical measurements confirm that the nanocolumns of oriented stacking of MoS 2 (O-MoS 2 ) have much better HER activity than bulk MoS 2 and randomly stacking of MoS 2 with about 25 times enhancement of electrochemically active surface area (ECSA). Therefore, assembling style along vertical inert plane may be a novel way to enhance HER performances of layered transition metal sulfides.