Highly stable “polymer network” of self-supported nickel-phosphorus-based catalytic electrodes at ampere-scale for overall seawater splitting

Constructing economical and corrosion-resistant catalytic electrodes for efficient and long-term stable hydrogen production from seawater splitting is extremely challenging and significant. Herein, a “polymer network” efficient and corrosion-resistant self-supported catalytic electrode (PANI-NiP@IF) is successfully constructed by in-situ etching of iron foam (IF) combined with the self-assembly of the conductive polymer aniline (PANI). The conductive PANI promotes electron redistribution and effectively reduces the activation energy of the hydrogen/oxygen evolution reaction (HER/OER) process, while its special core-shell structure forms a “network armour” to protect the catalytic active substances and improve the long-term stability of the catalytic electrode. In the alkaline electrolyte (1.0 M KOH+ 0.5 M NaCl), the overpotential of PANI-NiP@IF electrode in the HER and OER processes are only 196 mV and 231 mV at the current density of 100 mA cm⁻², and the voltage of overall water splitting (OWS) is only 1.899 V. More importantly, the PANI-NiP@IF electrode is able to continue stable catalysis for more than 350 h at a current density of 1.0 A cm⁻² after 400 h of catalysis at current densities of 10–500 mA cm⁻², demonstrating superior ampere-scale catalytic performance and stability. Simultaneously, this strategy is universally applicable to the catalysis of a series of conductive polymers (polypyridine and polypyrrole), which provides a strong theoretical support for the construction of efficient, economical and long-term stable catalytic electrodes for industrial-scale water splitting. © 2025 Elsevier B.V.