Electrochemical water splitting provides a means to store electricity generated from sustainable sources like wind and solar plants. As hydrogen is considered as a clean energy carrier, the need for catalysts is increasing and alternatives to platinum catalyst are needed. MoS2 is a promising alternative to Pt for HER catalysis. The alignment and number of layers can alter the catalytic activity of MoS2. However, controlling the formation of the 1T-MoS2 layers on surfaces remains challenging. The layer by layer (LbL) deposition method was used to control the MoS2 film thickness (mass loading) on the surface. The formation and height distribution of the layers were studied by atomic force microscopy (AFM) on Au(111) deposited on muscovite mica. Further characterization of 1T-MoS2 nanosheets stacked on the fluorine-doped tin oxide (FTO) surface was carried out by Raman, revealing E12g and A1g modes of MoS2 for sample with five deposition cycles or greater. The electrocatalytic activity of 1T-MoS2 layers, specifically the overpotential associated with the hydrogen evolution reaction (HER), was determined as a function of film thickness. The overpotential at a current density of -2 mA/cm2 decreased with an increase in mass loading, from 0.61 V for one deposition cycle to 0.54 V prepared by 20 deposition cycles. In order to directly compare the electrochemical activity of the two phases (1T vs. 2H) at a constant mass loading and surface area, the 1T-MoS2 deposited on the electrode surface was converted to the 2H phase by laser irradiation. For a given number of deposition cycles (i.e., similar mass loading), 1T-MoS2 exhibited a lower overpotential for the HER than the 2H-MoS2 phase. Our study provides a novel approach to control the formation of 1T-MoS2 layers on electrode surfaces for electrochemical applications.

Layer by layer deposition of 1T-MoS2 for water splitting reaction

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.