Hydrothermally synthesized a pyrochlore-type composite (rGO@Sr3Mn2O7) an effective electrocatalyst for Oxygen Evolution Reaction (OER)

Abstract

Numerous environmental issues, comprising global warming and depletion of fuel supplies forced the scientist to use ecologically friendly power generating sources in the modern world. Electrocatalytic water splitting (EWS) is greatly beneficial method for obtaining energy from renewable sources. However, the substantial overpotential (η) required for sluggish OER presents an obstacle to its extensive potential. We synthesized rGO@Sr₃Mn₂O₇ catalyst utilizing hydrothermal route to serve as an electrocatalyst for OER. The developed electrocatalyst exhibits enhanced OER performance in comparison to pure Sr₃Mn₂O₇. The prepared rGO@Sr₃Mn₂O₇ catalyst has undergone extensive examination through various analytical techniques. Electrocatalytic performance of fabricated rGO@Sr₃Mn₂O₇ was evaluated in 1 M alkaline media which revealed minimal η (195 mV), a less Tafel value (36 mV/dec) at current density (C_d) of 10 mA/cm² and least charge transfer resistance (R_ct = 0.18 Ω). Furthermore, the measured ECSA value for the composite was 1242 cm⁻², while the TOF value for the composite was 2.12 s⁻¹. The composite exhibited stability for (35 h), as assessed through chronoamperometry. The exceptional activity of produced catalyst can be attributed to rGO distributed on Sr₃Mn₂O₇ surface, which supports in improving electron conduction. The integration of rGO and Sr₃Mn₂O₇ leads to increased SSA, diverse active spots, reduced resistivity and exceptional stability, thereby enhancing the effectiveness of OER process. Hence, the electrocatalytic electrode displays noteworthy long-lasting durability for OER, presenting it as a favorably encouraging replacement to catalysts for future purposes.