Three-Dimensional Printed MoS2/Graphene Aerogel Electrodes for Hydrogen Evolution Reactions.

ABSTRACT

In this work, we demonstrate the use of direct ink writing (DIW) technology to create 3D catalytic electrodes for electrochemical applications. Hybrid MoS2/graphene aerogels are made by mixing commercially available MoS2 and graphene oxide powders into a thixotropic, high concentration, viscous ink. A porous 3D structure of 2D graphene sheets and MoS2 particles was created after post treatment by freeze-drying and reducing graphene oxide through annealing. The composition and morphology of the samples were fully characterized through XPS, BET, and SEM/EDS. The resulting 3D printed MoS2/graphene aerogel electrodes had a remarkable electrochemically active surface area (>1700 cm2) and were able to achieve currents over 100 mA in acidic media. Notably, the catalytic activity of the MoS2/graphene aerogel electrodes was maintained with minimal loss in surface area compared to the non-3D printed electrodes, suggesting that DIW can be a viable method of producing durable electrodes with a high surface area for water splitting. This demonstrates that 3D printing a MoS2/graphene 3D porous network directly using our approach not only improves electrolyte dispersion and facilitates catalyst utilization but also provides multidimensional electron transport channels for improving electronic conductivity.