In situ electrodeposition synthesis of CoP@NiFe LDH heterostructure as high-performance electrocatalyst for enhanced seawater electrolysis

Layered double hydroxides (LDHs) are highly regarded catalysts for oxygen evolution reaction (OER), but the application is limited by low conductivity and stability characteristics. In this work, the CoP@NiFe LDH heterostructure is obtained by a simple electrodeposition-phosphorization-electrodeposition method, and the establishment of heterostructure regulates the electronic configuration, which promotes the catalytic performance and stability. In simulated seawater, CoP@NiFe LDH reaches 100 and 300 mA cm−2 at overpotentials of only 260 and 278 mV, with Tafel slope of 44.4 mV dec−1, while also demonstrating remarkable stability. In situ Raman spectra indicate the conversion of Ni(OH)2 to Ni3+αOOH during the OER process, suggesting that the high valence Ni3+αOOH is the real active center, and the heterostructure efficaciously minimizes the overpotential that is necessary for the conversion to Ni3+αOOH, which is also confirmed by DFT calculations. Overall, this work presents a report on the process engineering and formulation of an energetic OER catalyst, which provides a viable solution for the industrialization of seawater electrolysis.