Ali A. Ensafi, N. Zandi-Atashbar, Z. Mohammadi, A. Abdolmaleki, B. Rezaei,

The main purposes of this work were minimizing the levels of expensive electrocatalyst such as platinum and palladium for maximizing hydrogen evolution at low overpotentials. Here, different compositions of platinum and palladium nanoparticles were applied so that the minimum amount of platinum as a high efficient HER electrocatalyst was achieved. Moreover, a newly prepared nanocomposite, 
sulfonated graphene-based conductive polymer (poly(3,4eethylene dioxythiophene), PEDOT),  was  used  as  a  sup- port of the loaded Pt and Pd nanoparticles. This prepared nanocomposite was assigned as PtxPd(1-x)NPs/ PEDOTeSG, which x was changed from 0.0 to 1.0. Preparation and performance of this nanocomposite were characterized using various analytical and electrochemical methods. The results obtained from voltammetry and impedance spectroscopy studies indicated different electrochemical manners of the electrocatalyst towards reducing  protons  into hydrogen,  contained various  compositions of  Pd and  Pt. Among these results, the highest Tafel slope and exchange current, as well as the lowest overpotential, were respectively determined as 57 mV decade-1, 0.301 mA and 0.1726 V (vs. Ag/AgCl), when the HER was investigated at Pt0.5Pd0.5NPs/PEDOTeSG/GCE. The nanocomposite remained stable until 500th cycle of the potential. Summarily, the results of this study were the preparation of the efficient, stable and low- cost HER electrocatalyst.

Keywords:
Hydrogen evolution reaction Sulfonated graphene nanosheets Nanoparticles decoration Electrocatalyst
Nanocomposite