Grafting Poly(acrylic acid) from PEDOT To Control the Deposition and Growth of Platinum Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution

Electrochemical water splitting is a sustainable, environmentally friendly method of hydrogen generation for green energy. However, the ideal electrocatalyst, platinum, is limited by cost and scarcity. Thus, new approaches are needed to minimize the amount of platinum required for efficient hydrogen production, while its electrocatalytic activity is retained. In this work, we report the development of a novel electrocatalyst based on platinum nanoparticles (PtNPs) deposited on conducting poly­(3,4-ethylenedioxythiophene) (PEDOT), grafted with poly­(acrylic acid) (PAA) chains. The presence of PAA controls the PtNP size and prevents aggregation during electrodeposition. The composite materials demonstrated enhanced electrocatalytic activity for the hydrogen evolution reaction (HER) in acid, with onset potentials as low as −84 mV vs RHE and exchange current densities up to 161 μA cm<sup>–2</sup>. Thus, these composite electrodes show promise as a straightforward, cost-effective alternative to conventional platinum HER catalysts. Furthermore, this novel fabrication approach shows great potential for the development of future electrocatalysts, providing an infinitely tailorable substrate for nanoparticle deposition thanks to the versatility of grafted conducting polymer films.