Inheritable Organic-Inorganic Hybrid Interfaces with π-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.

Automated summary

This study demonstrates the importance of rational heterointerface engineering for superior and robust hydrogen evolution reaction (HER). By constructing organic-inorganic hybrid heterojunctions, the researchers achieve strong electron coupling and optimal electronic structure for efficient HER. The resulting hybrid material exhibits low overpotentials and robust stability, making it a promising electrocatalyst.