Effectively Controlled Structures of Si-C Composites from Rice Husk for Oxygen Evolution Catalyst

Area of Science:

• Materials Science
• Electrochemistry
• Biomass Valorization

Background:

• Biomass-based carbon materials offer sustainable alternatives for energy applications.
• Utilizing the internal functional groups and unique structures of biomass is key for advanced materials.
• Rice husk, a silicon-rich biomass, presents challenges due to its intricate structure.

Purpose of the Study:

• To develop a method for regulating biomass-based carbon morphology for energy materials.
• To utilize the functional groups of rice husk-derived carbon as a stable substrate.
• To explore the application of these materials in electrocatalysis and hydrogen production.

Main Methods:

• Direct high-temperature carbonization of rice husk to form a cordyceps-like SiC structure.
• Chemical deposition to synthesize a silicon carbide-carbon@iron oxide (SiC-C@Fe3O4) oxygen evolution reaction catalyst.
• Electrochemical characterization in 1 M KOH electrolyte.

Main Results:

• A stable, highly interconnected cordyceps-like SiC structure was successfully synthesized from rice husk.
• The SiC-C@Fe3O4 catalyst exhibited excellent electrocatalytic performance: low overpotential (260 mV), low Tafel slope (56.93 mV dec⁻¹), high electrochemical active surface area (54.92 mF cm⁻²), and low Rct (0.15 Ω).
• The developed Si-C composite material overcomes limitations of silicon-rich biomass and demonstrates potential for hydrogen production.

Conclusions:

• The SiC-based substrate derived from rice husk provides a stable platform for next-generation energy materials.
• This approach enables high-value utilization of rice husk, broadening its application scope in electrocatalysis and water electrolysis for hydrogen production.
• The study offers a theoretical basis for using rice husks in sustainable energy technologies.