Interface Engineering via Ti₃C₂T MXene Enabled Highly Efficient Bifunctional NiCoP Array Catalysts for Alkaline Water...

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Developing efficient and stable non-noble metal electrocatalysts is crucial for advancing renewable energy systems, particularly for overall water splitting.
• Existing catalysts often face challenges related to cost, efficiency, and long-term stability, necessitating innovative material design.

Purpose of the Study:

• To fabricate a novel heterostructured electrocatalyst using non-noble metals for highly efficient and stable overall water splitting.
• To investigate the synergistic effects between nickel-cobalt phosphide nanoneedles and MXene for enhanced electrocatalytic activity.

Main Methods:

• Fabrication of a NiCoP nanoneedle array on a Ti3C2Tx MXene-coated Ni foam substrate (NCP-MX/NF) via dip-coating and hydrothermal methods, followed by phosphorization.
• Electrocatalytic performance evaluation for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media.
• Assessment of overall water splitting performance and long-term stability.
• Density Functional Theory (DFT) calculations to elucidate the interfacial catalytic mechanisms.

Main Results:

• The NCP-MX/NF catalyst exhibited superior electrocatalytic performance with low overpotentials (72 mV for HER, 303 mV for OER at high current densities) and low Tafel slopes (49.2 mV dec⁻¹ for HER, 69.5 mV dec⁻¹ for OER).
• The catalyst demonstrated excellent long-term stability for both HER and OER.
• Overall water splitting performance required low potentials (1.54 V at 10 mA cm⁻² and 1.76 V at 50 mA cm⁻²), surpassing the Pt/C∥IrO2 benchmark.
• DFT calculations confirmed the catalytic contribution of the NCP/Ti3C2O2 interface and analyzed adsorption energetics of intermediates.

Conclusions:

• The heterostructured NCP-MX/NF catalyst offers a promising non-noble metal alternative for efficient and durable overall water splitting.
• Synergistic effects between NCP and MXene significantly enhance electrocatalytic activity and stability.
• The developed fabrication method and catalyst design provide a viable pathway for next-generation electrocatalysts in renewable energy applications.