Craved Ni₃S₂–Sm₂O₃ heterojunction with enhanced electrocatalytic stability and oxygen evolution reaction

The search for stable, affordable, and active electrocatalysts that can efficiently produce hydrogen by water splitting is imperative to transition energy systems especially away from fossil fuels to a contemporary one. Herein, Ni₃S₂ integrated Sm₂O₃ composite (Ni₃S₂–Sm₂O₃) is produced by on nickel foam (NF) support espousing hydrothermal technique. All the pristine and composite materials including, Ni₃S₂, Sm₂O₃ and Ni₃S₂–Sm₂O₃ are explored for oxygen evolution reaction (OER). Amongst these, Ni₃S₂–Sm₂O₃ displayed an extraordinarily higher oxygen evolution activity at an overpotential of 225 mV and Tafel slope of 63 mV dec⁻¹ a current density of 50 mA cm⁻² is obtained. The pore volume and surface area of all the samples have been recorded using Brunauer–Emmett–Teller (BET). The optimized Ni₃S₂–Sm₂O₃ showed a higher surface area of 222 m² g⁻¹ which is higher compared with pristine Ni₃S₂ and Sm₂O₃. To elucidate morphological attributes of samples by scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The composite material Ni₃S₂–Sm₂O₃ demonstrated highly porous structures compared with pure materials. The boosted OER activity is related to the fast migration of charges, extraordinary stability and porous structure. The post-characterization of the produced electrode showed that the development of an oxide/oxyhydroxide layer on the surface of the catalyst supports continued outstanding OER activity.