Engineering CuNd_{(2–<i>x</i>)}Gd_<i>x</i>O₄@CNT Interfaces for Superior Electrocatalytic Water Splitting via Extensive Active Site Generation

Creation of a sustainable energy future necessitates the production of high energy density fuels like hydrogen. Ultimately, progress toward a hydrogen economy is intrinsically linked to advancements in electrocatalysts for efficient water electrolysis. In this study, CuNd(2–x)GdxO4 nanoparticles embedded on a CNT matrix were engineered as an efficient bifunctional electrocatalyst for total water splitting. The catalyst features a high density of active sites coupled with a significantly augmented surface area and optimized interfacial charge accumulation. These synergistic attributes promote efficient surface ion adsorption and product desorption, yielding an enhanced electrocatalytic activity. Consequently, the catalyst demonstrated robust performance, achieving overpotentials of 114 and 230 mV at 10 mA cm–2 for HER and OER, respectively, while maintaining remarkable stability for 50 h. The faradaic efficiency was found to be 95.55 and 95.82% for HER and OER, respectively. The experimental investigations further substantiated the concurrent action of both AEM and LOM mechanistic pathways governing electrocatalytic water splitting over the developed catalyst. As a high-performance alkaline water electrolyzer, the bifunctional electrocatalyst required 1.61 V at 10 mA cm–2. This study contributes valuable insights into the rational design and precise tuning of electrocatalysts to optimize the performance in sustainable energy generation.