Enhanced electrocatalytic activity of PtRu/nitrogen and sulphur co-doped crumbled graphene in acid and alkaline media.

The low mass activity and high price of pure platinum (Pt)-based catalysts predominantly limit their large-scale utilization in electrocatalysis. Therefore, the reduction of Pt amount while preserving the electrocatalytic efficiency represents a viable alternative. In this work, we prepared new PtRu nanoparticles supported on sulphur and nitrogen co-doped crumbled graphene with trace amounts of iron (PtRu/PF) electrocatalysts. The PtRu/PF catalysts exhibited enhanced electrocatalytic performance and stability for the hydrogen evolution reaction (HER) at pH = 0. Moreover, the prepared PtRu/PF electrocatalyst displayed higher HER activity than commercial 20% Pt/C. The PtRu/PF catalyst achieved a current density of 10 mA cm at an overpotential value of only 22 mV for HER, performing better activity than many other Pt-based electrocatalysts. Besides, the PtRu/PF revealed a good performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media. The PtRu/PF catalyst recorded a current density of 10 mA cm at an overpotential of only 270 mV for OER in KOH (1.0 M) solution and an onset potential of 0.96 V vs. RHE (at 1 mA cm) for ORR in KOH (0.1 M) solution.