Synergies of CoFe-LDH/CoMoP for efficient pH-universal and alkaline seawater electrolysis hydrogen evolution

In this work, CoFe-LDH/CoMoP/NF was obtained via electrodeposition. Firstly, CoFe-LDH was deposited on nickel foam (NF). Subsequently, CoMoP was deposited onto CoFe-LDH/NF for compositing. Through optimization of the deposition current for enhanced material properties, the CoFe-LDH/CoMoP/NF ultimately achieved optimal catalytic performance. Experiments have found that CoFe-LDH/CoMoP/NF exhibits excellent performances towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). At 100 mA cm −2 , the CoFe-LDH/CoMoP/NF electrode achieves overpotentials of 195 mV (acidic), 430 mV (neutral), 145 mV (alkaline), and 150 mV (alkaline seawater). The results of electrochemical testing and XPS after HER confirm that CoFe-LDH/CoMoP/NF has good stability. While for OER in alkaline seawater, CoFe-LDH/CoMoP/NF demonstrates excellent performance, with 1.595 V at 200 mA cm −2 . Notably, in alkaline seawater, CoFe-LDH/CoMoP/NF electrodes were utilized to assemble a two-electrode electrolytic cell, which can reach 100 mA cm −2 with 1.71 V. Furthermore, the Density Functional Theory (DFT) results confirm that CoFe-LDH/CoMoP improves the material’s electronic structure. This optimization lowers the hydrogen adsorption free energy barrier, and improves catalytic activity. This work provides new ideas for promoting water electrolysis across the full pH range, and can address the challenges of the actual seawater environment.