Coupling heterointerface engineering with morphological design for high-performance water-splitting electrocatalysts.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Non-noble-metal bifunctional electrocatalysts are crucial for water splitting but face challenges like low activity and stability.
• Existing catalysts often suffer from poor mass transport and degradation under operating conditions.

Purpose of the Study:

• To design and fabricate highly active and durable non-noble-metal electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).
• To address limitations in intrinsic activity, mass transport, and long-term stability of bifunctional electrocatalysts.

Main Methods:

• Fabrication of NiO/NiS2 heterostructured catalysts with a hierarchical porous architecture on biomass-derived N-doped carbon.
• Integration of heterointerface engineering and morphological engineering.
• Investigation of interfacial electronic redistribution and surface reconstruction under operating conditions.

Main Results:

• The NiO/NiS2 heterostructure exhibited optimized electronic structure and enhanced intrinsic catalytic activity.
• The hierarchical porous architecture improved mass-transfer efficiency due to superhydrophilic and superaerophobic properties.
• The catalyst achieved excellent overall water-splitting performance (10 mA·cm-2 at 1.52 V) with high stability (<5% decay after 100 h), outperforming noble-metal benchmarks.

Conclusions:

• The developed NiO/NiS2 catalyst offers a promising alternative to noble metals for efficient and stable water splitting.
• Synergistic heterointerface and morphological engineering are effective strategies for designing advanced non-noble-metal electrocatalysts.
• This work provides valuable mechanistic insights for future catalyst development.