Interwoven N-doped carbon nanotubes with capped Ni-doped FeP as double-functional electrocatalysts for overall seawater electrolysis

Seawater electrolysis technology powered by clean new energy is recognized as the most promising sustainable and green hydrogen preparation method. The extremely expensive and low reserve of commercially available noble metal electrocatalysts and the rapid inactivation of catalysts under complex ionic environments hamper their industrialization. Herein, a novel interwoven N-doped carbon nanotube (N-CNTs) structure capped with Ni-doped FeP nanoparticles (NFP@NC) is successfully developed by Ni-doped Fe cluster-catalyzed CNT growth process and the gas phosphating method. The unique interwoven nanotube network and strong interaction of Ni-doped FeP and N-CNTs provide fast mass transfer and gas bubble emission, as well as drastically enhanced stability. The NFP@NC presents an overpotential of 280 mV for the oxygen evolution reaction and 206 mV for the hydrogen evolution reaction at 10 mA cm−2, lower than most reported iron-based catalysts. This research provides an effective way to construct interwoven CNT networks as high-performance bifunctional seawater electrolysis catalysts.