Achieving ultra-stable hydrogen evolution at 2000 mA cm−2 via a hierarchical Pt electrocatalyst with dual charge/mass transfer networks

Designing electrocatalysts with rapid charge/mass transfer kinetics and robust stability is pivotal for achieving a high-performance electrocatalytic hydrogen production. Herein, a dual charge/mass transfer network with internal platinum anchored nitrogen-doped reduced graphene oxide (NrGO) nanoribbons and interlayered external carbon nanotubes (CNTs) has been engineered to construct a 3D hierarchical Pt@NrGO/CNTs electrocatalyst. Systematic studies reveal that the NrGO nanoribbons can not only efficiently anchor the Pt active sites via Pt–N bonding, avoiding the exfoliation induced by bubble rupture and electrolyte convection at a high current density, but also serve as an internal conductive network to continuously supply electrons and reactants to the Pt active sites. Moreover, the CNTs can serve as an external conductive network to reduce NrGO nanoribbons stacking, forming abundant channels for charge/mass transfer. The optimized Pt@NrGO/CNTs catalyst exhibits a remarkable hydrogen evolution reaction performance: its mass activity at 50 mV overpotential is 24.14 A·mg Pt −1 , which is 13.3 times than that of the commercial 20% Pt/C electrocatalyst, while maintaining stable operation for 300 h under 2000 mA cm −2 in a practical proton exchange membrane water electrolyzers. The numerical and molecular dynamics simulations further indicate that the constructed internal and external conductive network of Pt@NrGO/CNTs can enhance the H + and H 2 diffusion.