Thematic area of your work (nanomaterials and nanocomposites)

The role of ascorbic acid in HER enhancement of rGO-MoS2 nanocomposites
Karimipour M.1, Khazraei S.1, Molaei M.1
1 Department of Physics, Faculty of Sceince, Vali-e-Asr University, Rafsanjan, Iran
E-mail:m.karimipour@vru.ac.ir
Global warming and environmental deteriorating as a universal issue has tremendously motivated many researchers to focus on the renewable and clean energy sources. Hydrogen as a clean, safe, reproducible and sustainable source has attracted many attentions in various fields of hydrogen storage as fuel cells and hydrogen evolution reaction [1]. MoS2 as an abundant earth compound with a layered structure of S-Mo-S coupled via van der Waals interaction exhibited promising results as a competitive candidate for HER. On the other hand, graphene and reduced graphene oxide has shown high potential for such application due to its high surface area and facile charge transport to promote electrocatalyst properties of MoS2 [2]. The main challenge in the growth of MoS2 on rGO are the high onset potential and MoS2 stability [3]. 
We report a new method for the preparation of MoS2 (100)-reduced graphene oxide (rGO) nanocomposites for enhancement of HER. Ascorbic acid synergistically is applied to reduce graphene oxide and controls the sulfur content of MoS2 resulted in texturing of MoS2 (100) by up taking sulfur and proposing Mo(VI) oxidation state. A Tafel slope of 44 mV.dec-1, an exchange current of 0.62 mA.cm-2, over potential of 156 mV at 10 mA.cm-2 and onset potential of 25 mV was obtained. 

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