Chloride Corrosion Resistant Nitrogen doped Reduced Graphene Oxide/Platinum Electrocatalyst for Hydrogen Evolution Reaction in an Acidic Medium

Abstract

AbstractImpurities present in the electrolyte often interfere with the electrochemical performance of the electrocatalysts. A robust electrocatalyst can provide corrosion resistance towards the poisoning of contaminants in the electrolyzer. In this present work, N doped graphene and graphene with platinum nanoparticles (NPs) composites (RGO−Pt, U‐NGO−Pt, and A‐NGO−Pt) have been studied against chloride ion poisoning on the performance of hydrogen evolution reaction (HER) in acidic medium. Effect of chloride ion poisoning has been studied by adding Cl‐ ion ranging from 0.16 to 0.96 mM in 0.5 M H2SO4 electrolyte solution. Experimental data revealed that the activated N‐ doped graphene oxide (by KOH at 600 °C) and Pt NPs composite imparts the highest Cl‐ corrosion resistance due to the presence of more pyridinic and pyrrolic groups in the N doped graphene‐Pt composite catalyst. Electrochemical studies showed that A‐NGO−Pt displayed the highest exchange current density (3.20 mA cm−2) and it was nearly 1.3 and 7 times higher than that of RGO−Pt (2.43 mA cm−2) and U‐NGO−Pt (0.46 mA cm−2) respectively. Tafel slope for HER was improved from 35.5 (RGO−Pt) to 32.6 mV dec−1 (A‐NGO−Pt), indicating that the doping of N in the graphene plays an important role in the improvement of the catalytic activity of A‐NGO−Pt catalyst. The impedance spectroscopy, chronoamperometry, chronopotentiometry data in presence of 0.96 mM Cl− ion concentration, LSV curves, and ECSA values before after chronoamperometry for A‐NGO−Pt catalyst confirmed that it was a chloride ion‐resistant, stable and durable electrocatalyst for efficient hydrogen generation by the electrochemical water splitting.