Chloroplast-like porous bismuth-based core-shell structure for high energy efficiency CO₂ electroreduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction reaction (CO2RR) to formate is an economically viable energy conversion pathway.
• Designing efficient electrocatalysts is crucial for advancing CO2RR technologies.

Purpose of the Study:

• To design and synthesize novel chloroplast-like porous bismuth-based core-shell (CPBC) materials for CO2RR.
• To investigate the electrocatalytic performance of CPBC materials for CO2 reduction to formate.

Main Methods:

• Synthesis of CPBC materials with porous carbon shells and Bi@Bi2O3 cores.
• Electrochemical characterization including Faradaic efficiency and durability tests over a wide potential range.
• Evaluation of energy efficiency at different potentials.

Main Results:

• CPBC materials effectively enrich and transfer CO2 to the active Bi@Bi2O3 sites.
• The Bi2O3 layer transforms into an activated metastable phase, enhancing CO2 conversion to formate.
• CPBC-1 achieved a Faradaic efficiency (FEformate) >94% over -0.65 to -1.0 V and durability >72 h.
• Maximum energy efficiency reached 76.7% at -0.7 V, the highest among bismuth-based materials.

Conclusions:

• CPBC materials represent a novel class of nature-inspired electrocatalysts for efficient CO2RR.
• The designed core-shell structure and activated metastable phase are key to high performance.
• This work provides new perspectives for developing advanced CO2RR electrocatalysts.