Coral-Like LaNixFe1−xO3 Perovskite Catalyst for High-Performance Oxygen Evolution Reaction

Abstract

With the rare earth element La was selected as the A site and transition metal ions (Ni, Fe) as the B site of perovskite-type oxides with general formula ABO3, a series of LaNixFe1−xO3 (x = 0, 0.3, 0.5, 0.7, 0.8, 1.0) perovskite catalysts were prepared by sol-gel method to investigate their catalytic performance for oxygen evolution reaction (OER). The catalyst activity was screened by linear scanning cyclic voltammetry (LSV), Tafel curves, and electrochemical impedance spectroscopy (EIS). A group of electrochemical tests for LaNixFe1−xO3 with various Ni/Fe ratios indicate that LaNi0.8Fe0.2O3 catalyst exhibits excellent electrochemical activity, with a resistance to charge-transfer reaction (R ct ) of 5.942 Ω cm−2, overpotential of 391 mV, a Tafel slope of 102.8 mV dec−1, and electrochemical double-layer capacitance (C dl ) of 12.31 mF cm−1. The stability test after 15000 s proves that the optimized LaNi0.8Fe0.2O3 has better stability compared to pristine LaFeO3 and LaNiO3. In addition, LaNi0.8Fe0.2O3 also exhibits the largest electrochemical active area (ECSA = 307.75 cm2) and exchange current density (j o = 1.08 mA cm−2). This work provides reference for perovskite in improving oxygen evolution performance.