Surface-Exposed Single-Ni Atoms with Potential-Driven Dynamic Behaviors for Highly Efficient Electrocatalytic Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Trapping active sites on hollow supports improves mass transfer and atomic utilization.
• Developing efficient catalysts for the oxygen evolution reaction (OER) is crucial for energy conversion technologies.

Purpose of the Study:

• To synthesize single-Nickel (Ni) atoms decorated hollow S/N-doped football-like carbon spheres (Ni SAs@S/N-FCS) using a facile chemical vapor deposition strategy.
• To investigate the catalytic performance of Ni SAs@S/N-FCS for alkaline oxygen evolution reaction (OER).
• To elucidate the dynamic behaviors and the role of sulfur dopants in OER activity.

Main Methods:

• Chemical vapor deposition (CVD) for synthesizing Ni SAs@S/N-FCS.
• Carbonization of CdS@3-aminophenol/formaldehyde to create S/N-FCS.
• Operando X-ray absorption spectroscopy (XAS) and theoretical calculations.

Main Results:

• The Ni SAs@S/N-FCS catalyst demonstrated excellent OER performance with a low overpotential (249 mV at 10 mA cm⁻²) and a small Tafel slope (56.5 mV dec⁻¹).
• The catalyst exhibited ultra-long stability for OER, lasting up to 166 hours without significant degradation.
• Operando XAS and theoretical calculations revealed the dynamic behavior of Ni-N₄ sites and the contribution of sulfur dopants to OER activity.

Conclusions:

• The synthesized Ni SAs@S/N-FCS is a highly efficient and stable electrocatalyst for alkaline OER.
• The study provides insights into the active sites and the role of dopants in enhancing catalytic activity.
• This work offers a promising strategy for designing advanced catalysts for energy applications.