Spinel‐Type Metal Oxides with Tailored Amorphous/Crystalline Heterointerfaces for Enhanced Electrocatalytic Water Splitting

• Published in: Advanced functional materials 2024-12, Vol.34 (51), p.n/a
• Main Authors: Wang, Mengying, Feng, Xufang, Li, Shan, Ma, Yuxing, Peng, Yuxin, Yang, Shujiao, Liu, Yining, Lei, Haitao, Dang, Jingshuang, Zhang, Wei, Cao, Rui, Zheng, Haoquan
• Format: Article
• Language: English
• Subjects: amorphous/crystalline heterointerface; electrocatalysis; spinel‐type metal oxide; water splitting
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202410439

Metal oxides with spinel structure have garnered increasing attention as promising alternatives to noble metal‐based electrocatalysts. However, these electrocatalysts often fail to simultaneously exhibit high activity and stability for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), limiting their applications in electrocatalytic water splitting. Herein, crystalline/amorphous heterogeneous interfaces are successfully introduced into spinel NiCo2O4 nanosheets, which are grown in situ on carbon cloth (CC), denoted as NiCo2O4‐B‐CC. The amorphous/crystalline heterostructures combine the advantages of both phases in electrocatalysts. The amorphous phase of the spinel NiCo2O4 nanosheets modulates the electron density, provides abundant oxygen single vacancies as active sites, and enhances the corrosion resistance, while the crystalline phase improves conductivity. Density functional theory (DFT) calculations are performed to investigate the influence of surface oxygen single vacancy (SVO) on the activity of the OER and HER processes. The NiCo₂O₄‐B‐CC exhibits overpotentials of only 26 mV for HER and 215 mV for OER at a current density of 10 mA cm−2. It exhibits excellent electrocatalytic performance for water splitting, achieving a current density of 400 mA cm−2 at an applied voltage of 2.0 V. The construction of crystalline/amorphous heterogeneous interfaces in electrocatalysts provides novel approach for enhancing the electrocatalytic performance of metal oxides in water splitting. The introduction of crystalline/amorphous heterogeneous interfaces into spinel NiCo2O4 nanosheets, which are grown in situ on carbon cloth, represents a significant advancement in the development of electrocatalysts for overall water splitting. These heterostructures, combining both crystalline and amorphous phases, leverage the unique properties of each phase to enhance electrocatalytic performance.