Trimetallic Octahedral Ni–Co–W Phosphoxide Sprouted from Plasma-Defect-Engineered Ni–Co Support for Ultrahigh-Performance Electrocatalytic Hydrogen Evolution

The fundamental obstacle that only a few part of hydrogen energy is currently produced by industrial electrocatalysis, is in insufficient performance and high cost of even the most advanced catalysts. To meet the demand for high-performance, lasting catalysts at industry-relevant current densities (≥500 mA cm –2 ) with overpotentials ≤300 mV, here, we uniquely heterointerface the Ni, Co, and W phosphoxide phases in situ on plasma-defect-engineered Ni–Co support (M x O@M x P/PNCF (M = Ni, Co, W) core–shell heterostructure) to dramatically enhance the electrocatalytic performances with very high current densities. The achieved H 2 evolution requires low overpotentials of only 53 and 343 mV for current densities of 10 ( j 10 ) and 1000 mA cm –2 ( j 1000 ) and shows fast reaction kinetics with a small Tafel slope of 40 mV dec –1 . Importantly, the M x O@M x P/PNCF presents spectacular activity at industry-relevant current densities (> j 300 ) and outperforms the industry Pt/C benchmark. Our catalyst shows excellent long-term stability and durability with no significant activity loss after 10 4 cycles and 100 h of operation in an alkaline electrolyte. First-principles simulations reveal the best metal-phosphide combination to minimize the Gibbs energy for absorbing H + ions on the reactive sites and to enhance the desorption of H 2 .