Improvement of SnFe2O4 OER electrochemical property by Sm doping for water splitting

Electrocatalysts are crucial for achieving highly efficient renewable energy conversion and storage applications. Nevertheless, doping proves to be a successful approach in creating affordable spinel oxides that exhibit exceptional electrochemical capabilities. Our study focuses on the preparation of a samarium (Sm)-doped SnFe2O4 catalyst to expand the activity and stability of the oxygen evolution reaction (OER). However, the Sm-doped SnFe2O4 catalyst shows a highly encouraging overpotential of 179 mV at a current density of 10 mA cm−2 and a reduced Tafel slope of 32 mA dec−1. It maintains its durability for a duration of 40 h and even after undergoing 5000th cycles. The Sm-doped SnFe2O4 catalyst exhibits several positive effects, including reduced overpotential, higher catalytic current density, improved charge transfer kinetics (Rct = 0.29 Ω), and increased ECSA (111.62 cm2) value. These improved superior activity of Sm-doped SnFe2O4 catalyst can be attributed to factors such as its unique interconnected structures morphology, strong synergistic effects of Sm with Sn and Fe and the robust OH− adsorption, which are more pronounced compared to the un-doped SnFe2O4, which greatly enhanced their performance in OER activity. These findings indicate that by incorporating rare earth (Sm) dopant with a high valence state, spinel oxide can be fine-tuned to potentially enhance OER optimization for energy-producing applications.