Inheritable Organic-Inorganic Hybrid Interfaces with pi-d Electron Coupling for Robust Electrocatalytic Hydrogen Evolution at High-Current-Densities

Rational heterointerface engineering is crucial for superior and robust hydrogen evolution reaction (HER). Herein, a delicate organic-inorganic hybrid heterojunction based on the assembly of oxalate with polyaniline (PANI) for HER at high-current-densities is envisioned. Strong pi-d electron coupling is achieved between the delocalized pi electrons of PANI and the localized d electrons of oxalate metal sites. The CoC2O4 nanosheets are grown on nickel foam (NF) with Ni2+ ions substitution by the precursor etching. By virtue of the synergy of hetero ions and pi-d electron coupling, metal sites obtain sufficient exposure and electronic structure optimization. Surprisingly, the phase transition of oxalate during HER in the alkaline environment does not weaken the pi-d electronic coupling of the organic-inorganic hybrid interfaces. Inheritable interfacial electron interaction provides a reliable guarantee for robust stability at high-current-densities while endowing the hybrid materials with extremely low overpotentials. As expected, post-phase reconstructed Co0.59Ni0.41(OH)(2)@PANI/NF displays impressive HER activity, with a low overpotential of 43 mV@-10 mA cm(-2) and robust stability at -1000 mA cm(-2) for 30 h in the alkaline environment. This study sheds light on the rational heterostructure interface design and promotes the architecture of an impressive electrocatalysts system.