Activating Bismuth Nanosheets for Electrochemical CO₂ Reduction by Strain Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis
• Environmental Science

Background:

• Waste carbon dioxide (CO2) upgrading is crucial for environmental remediation.
• Bismuth-based materials are cost-effective catalysts for electrochemical CO2 reduction reaction (CO2RR).
• Controlling bismuth nanostructures' electronic structure for enhanced CO2RR remains a challenge.

Purpose of the Study:

• To engineer the electronic structure of bismuth nanosheets using compressive strain.
• To investigate the impact of strain engineering on the electrocatalytic performance of bismuth for CO2RR.
• To elucidate the mechanism behind strain-induced catalytic enhancement.

Main Methods:

• Fabrication of bismuth nanosheets with compressive strain (~0.6%) via an electrochemical cathodic method.
• Electrocatalytic evaluation of CO2RR performance, including efficiency and potential range.
• Density functional theory (DFT) calculations to understand the electronic structure modifications and binding energies.

Main Results:

• Bismuth nanosheets with compressive strain exhibited high electrocatalytic efficiency (>90%) for HCOO- formation from CO2 reduction.
• The strained bismuth nanosheets operated effectively over a wide potential range (700 mV).
• DFT calculations confirmed that compressive strain optimizes the binding of key intermediates (OCHO*).

Conclusions:

• Compressive strain engineering is an effective strategy to enhance the electrocatalytic activity of bismuth for CO2RR.
• Strain-induced electronic structure modification leads to improved catalytic performance by optimizing intermediate binding.
• This work presents a novel approach for developing high-performance CO2RR electrocatalysts through strain engineering.