Electrocatalytic behaviour of Cu-substituted La_0.5Sr_0.5Co_0.8Fe_0.2-xCu_xO_3-δ (x = 0–0.2) perovskite oxides

In this study, a series of La_0.5Sr_0.5Co_0.8Fe_0.2-xCu_xO_3-δ (x ​= ​0–0.2) perovskite oxides were synthesized following solution combustion technique. This elucidation highlights the role of partly substituted Cu on the OER performance of perovskite in alkaline media. XRD, BET surface area analysis, and XPS techniques were used to investigate the physio-chemical properties of the synthesized samples. XPS results revealed that partial substitution of Fe with Cu changed the oxidation states of Co and Fe (B-site) and substantially enhanced oxygen nonstoichiometry. Among the studied oxides, La_0.5Sr_0.5Co_0.8Cu_0.2O_3-δ oxide showed the highest catalytic activities in 1 ​M KOH for OER with a lower onset potential, over potential, and Tafel slope of 1.51 ​V, 500 ​mV, and 60.54 ​mV dec⁻¹ respectively with better long-term stability. Our findings indicate that La_0.5Sr_0.5Co_0.8Cu_0.2O_3-δ perovskite amends intrinsic properties providing efficient OER performance and may act as a more suitable electrocatalyst for OER application.