Synergistic effect of a bamboo-like Bi₂S₃ covered Sm₂O₃ nanocomposite (Bi₂S₃-Sm₂O₃) for enhanced alkaline OER

The availability of hydrogen energy from water splitting through the electrocatalytic route is strongly dependent on the efficiency, durability, and cost of the electrocatalysts. Herein, a novel Bi₂S₃-covered Sm₂O₃ (Bi₂S₃-Sm₂O₃) nanocomposite electrocatalyst was developed by a hydrothermal route for the oxygen evolution reaction (OER). The electrochemical properties were studied in 1.00 mol KOH solution after coating the target material on the stainless-steel substrate (SS). Physical analysis via XRD, FTIR, IV, TEM/EDX, and XPS revealed that the Bi₂S₃-Sm₂O₃ composite possesses metallic surface states, thereby displaying unconventional electron dynamics and purity of phases. The Bi₂S₃-Sm₂O₃ composite shows outstanding OER activity with a low overpotential of 197 mV and a Tafel slope of 74 mV dec⁻¹ at a 10 mA cm⁻² current density as compared to pure Bi₂S₃ and Sm₂O₃. Meanwhile, the composite catalyst retains high stability even after 100 h of the chronoamperometry test. Thus, this work unveils a new avenue for the speedy flow of electrons, which is attributed to the synergetic effect between Bi₂S₃ and Sm₂O₃, as well as enriched interfacial defects, which exhibit greater oxygen adsorption capability with improved electronic assemblies in the active interfacial region. In addition, the introduced porous structure in core-shell Bi₂S₃-Sm₂O₃ provides extraordinary electrical properties. Thus, this article offers a realistic framework for electrochemical energy generation.