Exploring Oxygen Vacancy Effect in 1D Structural SnIP for CO₂ Electro-Reduction to Formate.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• 1D nanostructures offer enhanced electron and ion transport for catalytic applications.
• Efficient conversion of carbon dioxide (CO2) to valuable products like formate is crucial for sustainability.
• Developing stable and active electrocatalysts for CO2 reduction reaction (CO2RR) remains a challenge.

Purpose of the Study:

• To synthesize and utilize a 1D van der Waals material, tin iodide phosphide (SnIP), as an electrocatalyst for CO2 to formate conversion.
• To investigate the effect of electrochemical treatment on SnIP structure and its catalytic performance.
• To enhance the activity and durability of CO2RR by introducing oxygen vacancies and stabilizing the catalyst's oxidation state.

Main Methods:

• Synthesis of 1D tin iodide phosphide (SnIP) nanostructures.
• Electrochemical treatment of SnIP to induce structural reconstruction and oxygen vacancy formation.
• Electrocatalytic testing for CO2 reduction reaction (CO2RR) to formate.
• Characterization of catalyst structure, surface properties, and electrochemical performance.

Main Results:

• Electrochemical treatment transformed SnIP into a web-like structure with increased oxygen vacancies.
• The generated oxygen vacancies significantly promoted CO2RR activity and formate selectivity.
• The catalyst achieved >92% formate faradaic efficiency (FEformate) at 300 mA cm-2, with a maximum partial current density of 343 mA cm-2.
• Excellent long-term stability was demonstrated (>100 h at 100 mA cm-2 with >86% FEformate).

Conclusions:

• Electrochemical generation of oxygen vacancies in 1D SnIP is an effective strategy to boost CO2RR performance.
• Stabilizing the catalyst's oxidation state through oxygen vacancies improves CO2RR durability.
• This work presents a facile method for creating defect-rich catalysts for efficient CO2 conversion.