Electric field-assisted synthesis of bifunctional ultralow Pt/pore-defective graphene composite for hydrogen evolution reaction and ethanol oxidation reaction

Designing efficient electrocatalysts that synergistically optimize hydrogen evolution reaction (HER) and ethanol oxidation reaction (EOR) pathways remains a critical challenge for sustainable energy conversion. Here, we report a platinum nanocluster-anchored defect-engineered graphene catalyst (Pt/G) synthesized via exfoliation process coupled with solvothermal reduction. By modulating calcination temperature (600 °C) and KOH etching, we achieve ultrafine Pt nanoclusters (1.65 nm ± 0.39 nm) uniformly dispersed on defect-rich graphene, balancing Pt loading (0.95 wt%) and defect density (I D /I G  = 0.15). The optimized Pt/G exhibits exceptional HER activity, requiring only 37 mV overpotential to deliver 10 mA cm −2 in acidic media, outperforming Pt/G-700 and Pt/G-500 counterparts. Mechanistic studies reveal that defect-mediated electronic coupling lowers hydrogen adsorption free energy (ΔG H ∗) and accelerates Volmer-Heyrovsky kinetics, yielding a Tafel slope of 26.12 mV dec −1 . For EOR, Pt/G demonstrates a mass activity of 1234.5 mA mg Pt −1 , 2.18 times higher than unetched sample. This is attributed to weakened CO intermediate binding and enhanced OH ads accessibility. Characterization results confirm that defect-rich graphene stabilizes Pt clusters against aggregation while promoting charge transfer (R ct  = 27.83 Ω). This work establishes a universal strategy for engineering metal-support interactions to advance multifunctional electrocatalysts toward energy-efficient hydrogen production and biofuel utilization.