Highly dispersed copper phosphide nanoparticles accelerate the electrolytic water oxidation process

Abstract

Currently, transition metal phosphides (Cu, Fe, Co, and others) have been identified as potential candidates for both the oxygen evolution reaction (OER, anode) and hydrogen evolution reaction (HER, cathode). One of the copper based phosphides has shown efficiency for the HER, however, it displays greater theoretical potential and instability compared to noble metal materials in the OER process. Herein, Cu–MOF–NH₂ nanocubes were subjected to pyrolysis treatment in a low phosphorus atmosphere to produce highly dispersed Cu₃P nanoparticles. Dispersed Cu₃P nanoparticles coated with nitrogen–carbon matrix composite layers provide numerous active sites and high stability. In situ Raman spectra confirmed a significant reduction in Cu⁺ oxidation to Cu²⁺. Furthermore, according to XPS resolution results, the Cu–P bond provides electrons to the Cu–P–O bond, thus accelerating the OER process. We integrated experimental electrochemistry to verify the potential enhancement of the OER performance and stability of Cu₃P using appropriate nanostructure coating techniques.