Direct Conversion of Metal Organic Frameworks into Porous Rugby Phosphides by Plasma for Oxygen Evolution

Abstract

Electrolytic seawater is a green, sustainable, and promising approach for hydrogen production. Benefiting from the cost-effectiveness, crystal structures, and tailorable modification, transition metal phosphides become a highly attractive catalyst for the electrolysis of water. Considering the sufficient exposure and intrinsic catalytic activity of metal sites, here, carbon layer-coated NiFeP nanocrystals with a porous rugby structure are synthesized by Ar–H₂ plasma. Activated PH radical in plasma is the key point to achieve phosphatization at a low temperature. The obtained porous rugby NiFeP catalyst exhibits excellent catalytic activity under alkaline conditions (300 mV in freshwater and 370 mV in seawater, 1000 mA cm^–2), good corrosion resistance, and superior operational stability (>100 h). Theoretical calculations prove that Fe introduction and subsequent phosphorization weaken the adsorption of *O and *OH, thus improving the oxygen evolution reaction performance. Plasma phosphorization offers exciting opportunities for the in situ modification of other types of framework materials.