Design of highly efficient FeWB snow-crust (SC) bifunctional electrocatalyst towards accelerated water-splitting under industrial operational conditions

Developing highly efficient electrocatalysts is crucial for electrochemical water-splitting, which is essential for generating clean and sustainable hydrogen energy and achieving global carbon neutrality. Herein, FeWB snow-crust (SC) electrocatalyst is fabricated via hydrothermal reaction and vacuum annealing treatment. The FeWB demonstrates relatively low overpotentials 246 mV and 135 ​mV at 100 ​mA/cm 2 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), placing it among the top-performing OER electrocatalysts. The bifunctional FeWB exhibits an exceptionally lower 2-E cell voltage of 2.96 ​V over the convention benchmarks of Pt/C || RuO 2 at 2 000 ​mA/cm 2 in 1 ​M KOH. Stability is evaluated by operating for over 6 days under harsh industrial conditions (6 ​M KOH at 60 ​°C) without any signs of degradation. Due to superior OER characteristics, the hybrid configuration of Pt/C || FeWB demonstrates a lower cell potential of 2.51 ​V in 6 ​M KOH at 2 000 ​mA/cm 2 . Kinetic electron transfer from B to Fe and W can create electron-enriched metallic reaction centers that are highly active for speedy splitting reactions. Additionally, the FeWB SC electrocatalyst exhibits a larger electrocatalytic surface area, improved intrinsic properties and high conductivity, which are imperative for accelerating the absorption/desorption of reaction intermediates towards catalysis. Multifunctional FeWB snow-crust (SC) demonstrates highly efficient overall water-splitting (OWS) performance better than the benchmark electrocatalysts of Pt/C || RuO 2 . Especially, the bifunctional system (FeWB || FeWB) demonstrates a low 2.96 ​V 2-E cell potential, while the hybrid configuration (Pt/C || FeWB) shows ultra-low 2.61 ​V in 1 ​M KOH at 2000 ​mA/cm 2 high current density.