رزگار احمدی

Relying on non-renewable fossil fuel resources to supply our growing energy demands has a dangerous dark side. Hydrogen was introduced as a renewable, clean and cheap alternative source of energy since two decades ago. Platinum (Pt) derivatives are the most popular catalyst to accelerate the hydrogen evolution reaction (HER) from electrolysis of water or acidic aqueous solution, but the high cost of Pt catalyst limited its widespread application. Tremendous efforts have been focused on the cost-effective hydrogen production catalysts. Transition metal chalcogenides (TMCs) such as MoS2 and MoS3 are scientifically and economically considered because of their abundance and capability in electronic, catalysis and so on. The objective of our project is designing an electrocatalyst or photoelectrocatalyst based on MoS2 and MoS3 thin film substrate for HER. Accordingly, a thin layer of MoSx nanostructure is electrochemically deposited on the surface of different electrodes such as glassy carbon electrode (GCE), gold (Au) and indium thin oxide (ITO). Morphology of the electrode surface is investigated by scanning electron microscopy. Electrochemical investigation revealed the highest catalytic activity for MoS3/Au electrode where, exhibits an onset overpotential of HER as low as -0.17 V vs. RHE electrode, and a Tafel slope as well as Pt/carbon catalyst in 0.5 M H2SO4 aqueous solution. An increased catalytic activity and stability of MoS3 is achieved when the graphene is utilized as substrate or substituted by cobalt oxide.