Grafting of Pd on Covalently and Noncovalently Modified N-Doped Graphene for Electrocatalysis

Hydrogen evolution reaction (HER) is considered to be a fundamental solution for procuring clean energy. Palladium is one of the most catalytically active metals toward HER. Here, an electrocatalyst is designed where palladium nanoparticles (Pd NPs) are immobilized on the surface of nitrogen-doped reduced graphene oxide. A comparative study of two different nitrogen doping strategies is employed wherein covalent incorporation of nitrogen (N) source and noncovalent attachment of 1-aminopyrene to graphene lattice is carried out. The morphological and physicochemical characteristic studies confirmed that the doping is successful over the carbon lattice, followed by nucleation of Pd NPs over N sites. Electrocatalytic activity of these two different catalysts toward HER is examined using the linear sweep voltammetry technique. It is found that Pd anchored covalently N modified carbon outperforms the 1-aminopyrene based catalyst. These findings will have a profound impact upon the designing of application specific electrocatalysts.