Bionic Construction of Helical Bi₂ O₃ Microfibers for Highly Efficient CO₂ Electroreduction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Bismuth(III) oxide (Bi2O3) is a promising material for electrocatalysis.
• Developing efficient catalysts for CO2 electroreduction is crucial for sustainable energy and chemical production.
• Tailoring material structures can enhance catalytic performance.

Purpose of the Study:

• To synthesize helical bismuth(III) oxide microfibers (HBM) using a cotton template.
• To investigate the catalytic activity and selectivity of HBM for CO2 electroreduction to formate.
• To explore the structure-performance relationship in HBM for enhanced electrocatalysis.

Main Methods:

• Preparation of HBM via a simple heating treatment using a cotton template.
• Electrochemical characterization in an H-cell and a flow cell.
• Analysis of catalytic performance, including faradaic efficiency and partial current density.

Main Results:

• HBM exhibited outstanding activity and selectivity for CO2 electroreduction to formate.
• A formate faradaic efficiency of 100.4±1.9% was achieved at -0.90 V vs. RHE in an H-cell.
• A partial current density of 226 mA cm⁻² with 96% formate faradaic efficiency was obtained at -1.08 V vs. RHE in a flow cell.

Conclusions:

• The helical structure of HBM induces lattice strains and enriches oxygen vacancies, promoting active site exposure.
• HBM demonstrates high performance as an electrocatalyst for CO2 conversion to formate.
• This bionic strategy offers a new pathway for designing high-performance metal oxide fiber electrocatalysts.