Graphene quantum dots assisted 1T/2H phase MoS2 as an efficient catalyst for the hydrogen evolution reaction

ShengFu Chen^1*, Yun‑Liang Soo¹

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:ShengFu Chen, email:jackey30218@gmail.com

Replacing platinum catalysts with Transition Metal Dichalcogenides (TMDC) as electrocatalysts for the hydrogen evolution reaction is of great significance. Slow reaction kinetics and electron transport efficiency are great challenges in efficient TMDC catalysts. Here, we report a composite material with 1T/2H phase Molybdenum disulfide (MoS2) and Graphene quantum dots (GQDs). MoS2 was prepared using Li-ion intercalation method. GQDs were prepared using Pyrolysis Carbonization method from citric acid. Thereinto, GQDs enhance the catalytic performance of MoS2 active sites due to their rich defect edges. And GQDs that are sticky and hydrophilic can greatly improve the adsorption of MoS2 on the substrate and increase the catalytic area. High proportion and stable 1T-phase MoS2 also improved conductivity. Therefore, GQDs doped 1T/2H-MoS2 show excellent catalytic performance, driving a current density of 10 (mA/cm2) and a Tafel slope of 57.2 mV dec-1 in acidic media with only 135.4 mV. Also, performance can be maintained for at least 1000 cycles with negligible drop. The results can be applied to design commercial-value and high-efficiency electrodes.

Keywords: 2D-materials, hydrogen evolution reaction, Graphene quantum dots, Molybdenum(IV) disulfide