Pr-doped NiFe-layered double hydroxide on plasma-etched nickel foam as a high-efficiency electrocatalyst for oxygen evolution reaction

Nickel-iron layered double hydroxide (NiFe-LDH), as a highly promising non-precious metal catalyst for the oxygen evolution reaction (OER), still suffers from several inherent drawbacks, including poor electrical conductivity, insufficient exposure of active sites, and a decline in performance under high current densities. These limitations severely restrict its practical application in the oxygen evolution reaction. Herein, a nanosheet morphology Pr-doped NiFe layered double hydroxide catalysts (Pr-NiFe-LDH) was synthesized <i>in situ</i> on the surface of Nickel foam modified by dielectric barrier discharge (DBD) plasma (PNF). The addition of Pr elements can effectively adjust the electronic structure of NiFe-LDH, change the position of the d-band center, and increase the number of active sites, thereby enhancing the catalytic activity. The overpotential of Pr-NiFe-LDH was reduced to 321 mV at 100 mA cm^-2, significantly lower than that of NiFe-LDH (342 mV) and even superior to that of commercial RuO₂ catalyst (441 mV). The density functional theory (DFT) study indicates that adding Pr to the surface of NiFe-LDH enhances its performance in the OER. This work not only deepened the understanding of the OER mechanism in the NiFe-LDH catalyst, but also provided valuable insights for the design of efficient, low-cost and noble-metal-free electrocatalysts.