Principal Component Analysis–Guided Design for Efficient Bifunctional Electrocatalysis

In this study, a series of cerium doped modified nickel sulfide electrode materials were prepared using hydrothermal synthesis technology, including Ni 9 S 8 , Ce-Ni 9 S 8 -1, Ce-Ni 9 S 8 -2, and Ce-Ni 9 S 8 -3. Through electrocatalytic experiments, we observed that the material exhibits excellent HER and OER performance, demonstrating outstanding dual catalytic properties for hydrogen and oxygen evolution. In the four comparative experiments, during the oxygen evolution reaction, the overpotential of Ce-Ni 9 S 8 -3 electrode material was the lowest. At current densities of 100, 150, 200 mA cm −2 , the overpotential of Ce-Ni 9 S 8 -3 electrode material was 264.6, 310.6, 348.6 mV, and the lowest slope of Ce-Ni 9 S 8 -3 was 19.39 mV/dec, but the activity was not the highest, confirming the excellent growth of our material. The overpotential of Ce-Ni 9 S 8 -3 electrode material was 331.4, 310.4, 285.4 mV.