Ultra-small intermetallic NiZn nanoparticles: a non-precious metal catalyst for efficient electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Traditional synthesis of intermetallic nanoparticles often leads to sintering and polydispersion.
• Achieving monodisperse, ultra-small intermetallic nanoparticles remains a significant challenge.

Purpose of the Study:

• To develop a novel, low-temperature solution chemistry route for synthesizing monodisperse intermetallic NiZn nanoparticles.
• To evaluate the electrocatalytic performance of these nanoparticles for the oxygen evolution reaction (OER).

Main Methods:

• Chemical conversion of metal nanoparticles into an ordered NiZn alloy using an organometallic zinc precursor.
• Low-temperature solution chemistry route preserving nanoparticle morphology.

Main Results:

• Successfully synthesized ultra-small, monodisperse intermetallic NiZn nanoparticles.
• Achieved high electrocatalytic performance for OER with a low overpotential (283 mV at 10 mA cm⁻²) and Tafel slope (73 mV dec⁻¹).
• Demonstrated superior OER efficacy compared to Ni$_{0.7}$Zn$_{0.3}$ alloy, pure Ni, and RuO$_{2.

Conclusions:

• The atomic ordering and synergistic effects in NiZn nanoparticles enhance intrinsic catalytic activity for OER.
• The developed method provides a general route for producing nanoscale alloys.
• The synthesized NiZn nanoparticles are highly efficient and durable electrocatalysts for energy conversion.