Enhanced borohydride electrocatalysis through electronic coupling of PtNi nanomaterials and reduced graphene oxide

In this study, a PtNi nanocomposite supported on reduced graphene oxide (rGO) was synthesized via a chemical reduction method, and its electrocatalytic performance for the electrochemical oxidation of sodium borohydride (NaBH₄) was investigated. The structural and morphological properties of the synthesized PtNi@rGO nanocomposite were characterized in detail using FTIR, XRD, TEM, and SEM-EDX analyses. The characterization results demonstrated that the PtNi alloy nanoparticles were successfully immobilized on the rGO surface and were homogeneously distributed in the 20-50 nm size range. Electrochemical performance studies were conducted using the cyclic voltammetry method in a solution containing 1 M NaOH and 0.1 M NaBH₄. The results revealed that the PtNi@rGO electrocatalyst achieved a maximum current density of 19.57 mA cm⁻², while under the same conditions, the PtNi and Pt electrodes exhibited values of 17.19 and 6.53 mA cm⁻², respectively. Furthermore, the determined initial potential of 0.13 V for PtNi@rGO indicated a faster reaction kinetics compared to the PtNi (0.17 V) and Pt (0.22 V) electrodes. Analyses conducted at different scan rates demonstrated that the reaction proceeded in a kinetically controlled manner and that the rGO support significantly improved charge transfer processes. Long-term stability tests have demonstrated that the developed nanocomposite maintains its electrocatalytic performance. The results indicate that the PtNi@rGO nanocomposite is a stable and promising electrocatalyst with high activity for hydrogen production via the electrooxidation of NaBH₄.