Fabrication of Hydrogen Evolution Reaction Electrocatalysts via Pyrolysis of Prussian Blue Based Composites with Polyaniline and Polypyrrole As Matrices

The paper studies the way of fabricating hydrogen evolution reaction (HER) electrocatalysts via pyrolysis of chemically synthesized composites based on conductive polymers (polyaniline, polypyrrole) with Prussian blue inclusions. Depending on the type of polymer in the initial composite, products of Prussian blue pyrolysis may differ. The use of polyaniline results in ultrafine spherical Fe₃N particles, whereas polypyrrole facilitates the formation of both spherical and cylindrical Fe₃С particles. The particles are formed within carbon matrices the structure of which is characterized by a significant amount of defects because of their doping with nitrogen atoms. The composite containing Fe₃C inclusions, which was obtained with the use of polypyrrole, has a high enough electrocatalytic activity in acidic electrolyte, with its hydrogen evolution current density being of 10 mA/cm² at overpotential of ‒230 mV.