Protein-Templated Fe and Ni Subnanoclusters for Advanced Energy Storage and Electrocatalysis.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Downsizing metal nanoparticles to nanoclusters and single atoms enhances atom utilization efficiency for energy applications.
• Developing cost-effective and high-performance electrode materials is crucial for advanced energy storage and conversion.

Purpose of the Study:

• To synthesize iron and nickel subnanoclusters embedded in a porous carbonaceous framework for energy applications.
• To evaluate the performance of these nanoclusters as electrodes in supercapacitors and for oxygen evolution reactions.

Main Methods:

• Bovine serum albumin-templated synthesis of iron and nickel nanoclusters.
• Hydrothermal compositing with graphene oxide and KOH-catalyzed pyrolysis.
• Fabrication of a hierarchically porous protein/graphene-derived carbonaceous aerogel.
• Electrochemical characterization for supercapacitor and oxygen evolution reaction performance.
• Molecular dynamics and density functional theory calculations for mechanistic insights.

Main Results:

• Carbon-supported Fe subnanoclusters (FeSNC) and Ni subnanoclusters (NiSNC) were successfully synthesized.
• FeSNC and NiSNC electrodes exhibited high specific capacitance (373 F g^-1 and 1125 F g^-1, respectively).
• A hybrid supercapacitor-battery device achieved high specific energy (47 Wh kg^-1) and power (18 kW kg^-1) with excellent cycling stability (>12,000 cycles).
• FeSNC demonstrated a lower oxygen evolution overpotential (270 mV) than the RuO₂ benchmark (328 mV).

Conclusions:

• The developed synthetic strategy effectively produces metallic subnanoclusters for energy applications.
• The subnanocluster-based electrodes show promising performance for supercapacitors and electrocatalysis.
• This approach offers a pathway for designing advanced materials for next-generation energy storage and conversion technologies.