Recently, the research team led by Professor Yanfeng Zhang from the Department of Materials Science and Engineering, College of Engineering at Peking University has made an important progress in controllable growth of monolayer MoS2 and the application in hydrogen reaction. The result titled “Controllable growth and transfer of monolayer MoS2 on Au foils and its potential application in hydrogen evolution reaction” has been published in the famous journal ACS Nano (DOI: 10.1021/nn503211t).

Transition metal dichalcogenides (TMDCs) with lamellar structures have drawn great interest due to its sizable band gap with indirect to direct tunability from bulk to monolayer, and plenty of intriguing performances in electrical, optical, and photovoltaic devices. In particular, theoretical calculations have indicated that the free energy of hydrogen bonding to the Mo terminated edge of MoS2 is close to that of Pt, which makes MoS2 a potentially low-cost, high-abundance substitute of Pt in electrocatalytic hydrogen evolution reaction (HER). However, controllable synthesis of domain size tunable MoS2 is essential for fulfilling the application potentials in HER.

Herein, Zhang’ group demonstrates, for the first time, the scalable synthesis of monolayer MoS2 on commercially available Au foils via a facile low-pressure CVD (LPCVD) method. Notably, the edge length of the triangular monolayer MoS2 flake is found to be tunable from nanometer to micrometer by varying the growth temperature or the precursor substrate distance. Of particular interest, the nano-sized triangular MoS2 flakes on Au foils are proven to be excellent electrocatalysts for HER, featured by a rather low Tafel slope (61 mV/decade) and a relative high exchange current density (38.1μA/cm2).

Zhang’ group also reported controllable growth of monolayer MoS2 and WS2 on sapphire and SrTiO3 substrate. (ACS Nano 2013, 7, 8963; ACS Nano 2014, 8, 8617), and comprehensively expounded the methods for growth of monolayer TMDCs in the famous journal Chem. Soc. Rev (DOI: 10.1039/c4cs00258j).

The first author of this article is Jianping Shi, a Ph. D. candidate of the College of Engineering.

This work was financially supported by National Natural Science Foundation of China (Grants Nos.51222201, 51290272, and 21201012) and the Ministry of Science and Technology of China (Grants Nos. 2011CB921903, and 2012CB921404).