LaCo0.2Fe0.8O3 perovskites doped with natural Ca2+ as bifunctional electrocatalysts for oxygen evolution and reduction reactions

Abstract

Perovskite oxides are promising electrocatalysts for various energy applications due to their exceptional catalytic activity, flexible architecture, and low cost. In this study, LCFO was doped with different ratios of Ca²⁺ from eggshells, resulting in dual-purpose electrocatalysts for oxygen reduction and evolution processes. The nanoparticles were characterized using various techniques, including Brunauer–Emmett–Teller analysis and XRD. Results clarified the relative surface area and roughness, increasing with Ca²⁺ doping. LCFO also demonstrated highly magnetic properties, improved charge transfer, catalytic activity, and long-term durability. The results demonstrated the perovskite's cost-effectiveness as a bifunctional electrocatalyst, and the role of Ca²⁺ in enhancing its properties. La_0.6Ca_0.4Co_0.2Fe_0.8O₃(LCCFO-0.4) showed higher magnetic properties (M_s = 13.36 emu g⁻¹ and M_r = 2.54 emu g⁻¹). The LCFO sample showed a current density of 5.13 mA cm⁻² and 3 mA cm⁻² for OER and ORR respectively, at E_onset 1.7 V and 0.57 V (vs. RHE). The LCFO electrochemical active surface area is 0.033 cm²