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

摘要

Rational heterointerface engineering is crucial for superior and robusthydrogen evolution reaction (HER). Herein, a delicate organic-inorganichybrid heterojunction based on the assembly of oxalate with polyaniline(PANI) for HER at high-current-densities is envisioned. Strong π-d electroncoupling is achieved between the delocalized π electrons of PANI and thelocalized d electrons of oxalate metal sites. The CoC_2O_4 nanosheets aregrown on nickel foam (NF) with Ni~(2+) ions substitution by the precursoretching. By virtue of the synergy of hetero ions and π-d electron coupling,metal sites obtain sufficient exposure and electronic structure optimization.Surprisingly, the phase transition of oxalate during HER in the alkalineenvironment does not weaken the π-d electronic coupling of the organicinorganichybrid interfaces. Inheritable interfacial electron interactionprovides a reliable guarantee for robust stability at high-current-densitieswhile endowing the hybrid materials with extremely low overpotentials. Asexpected, post-phase reconstructed Co_(0.59)Ni_(0.41)(OH)_2@PANI/NF displaysimpressive 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 andpromotes the architecture of an impressive electrocatalysts system.