Pencil Graphite Electrodes Decorated with Platinum Nanoparticles as Efficient Electrocatalysts for Hydrogen Evolution Reaction.

Platinum-based materials are widely known as the most utilized and advanced catalysts for hydrogen evolution reaction. For this reason, several studies have reported alternative methods of incorporating this metal into more economical electrodes with a carbon-based support material. Herein, we report on the performance of pencil graphite electrodes decorated with electrochemically deposited platinum nanoparticles as efficient electrocatalysts for hydrogen evolution reaction. The electrodeposition of platinum was performed via pulsed current electrodeposition and the effect of current density on the electrocatalytic activity was investigated. The obtained electrodes were characterized using cyclic voltammetry, while the electrocatalytic activity was assessed through linear sweep voltammetry. Field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy were utilised to gain an insight into surface morphology and chemical analysis of platinum nanoparticles. The best performing electrocatalyst, at both low and high current densities, was characterized by the highest exchange current density of 1.98 mA cm -2 and an ultralow overpotential of 43 mV at a current density of 10 mA cm -2 . The results show that, at low current densities, performances closest to that of platinum can be achieved even with an ultralow loading of 50 µg cm -2 Pt.