Designing Donor-Acceptor Interfaces with Built-In Electric Potential Using Hierarchically Grown NiTe-CeO₂...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are vital for the oxygen evolution reaction (OER), a key process in energy conversion.
• Non-noble metal-based heterojunctions offer a promising avenue for developing cost-effective and stable OER catalysts.
• Understanding interfacial charge transfer mechanisms is crucial for optimizing catalyst performance.

Purpose of the Study:

• To design and synthesize a NiTe/CeO₂ heterojunction electrocatalyst for the oxygen evolution reaction (OER).
• To investigate the interfacial synergy and charge transfer dynamics between NiTe and CeO₂.
• To evaluate the catalytic activity and stability of the designed heterojunction for OER.

Main Methods:

• Fabrication of NiTe/CeO₂ heterojunction via a donor-acceptor approach.
• Characterization using Kelvin probe force microscopy (KPFM) to study work functions and charge transfer.
• Electrochemical measurements including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy (EIS).
• Analysis of electrochemical active surface area (ECSA) and charge transfer resistance.
• Distribution of relaxation time (DRT) analysis to probe charge transfer kinetics.

Main Results:

• The NiTe/CeO₂ heterojunction exhibited a low overpotential of 263 mV at 10 mA cm^-2 and a Tafel slope of 81 mV dec^-1 for OER.
• KPFM confirmed facilitated charge transfer at the NiTe/CeO₂ interface due to work function matching.
• The heterojunction demonstrated an increased electrochemical active surface area (10.5 μF cm^-2) and reduced charge transfer resistance (1 Ω).
• Improved turnover frequency (3 s^-1) and enhanced OER kinetics were observed compared to bare NiTe.
• DRT analysis revealed accelerated charge transfer kinetics across the heterojunction interfaces.

Conclusions:

• The NiTe/CeO₂ heterojunction effectively modulates electronic structure via interfacial synergy, boosting OER performance.
• The donor-acceptor design and built-in electric field formation are key to the enhanced catalytic activity and stability.
• This work provides a new strategy for designing efficient non-noble metal-based electrocatalysts for OER.