Sulfur-Doping Tailors BiOI for High-Efficiency Cocatalyst-Free Piezocatalytic H₂ Evolution

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Piezocatalytic water splitting is a key technology for green hydrogen production.
• Current methods often require expensive noble metal cocatalysts, limiting scalability.
• Optimizing piezoelectric materials without noble metals is crucial for sustainable energy.

Purpose of the Study:

• To investigate tailoring defect chemistry in piezoelectric materials for enhanced catalytic activity.
• To develop a noble-metal-free piezocatalyst for efficient hydrogen evolution.
• To explore the impact of sulfur substitution on BiOI's piezocatalytic performance.

Main Methods:

• Synthesis of sulfur-substituted BiOI via anion exchange (O²⁻ → S²⁻).
• Characterization of material properties using experimental and theoretical analyses.
• Evaluation of piezocatalytic hydrogen (H₂) evolution activity.

Main Results:

• Achieved a 2.8-fold increase in H₂ evolution activity with 10% sulfur-substituted BiOI (3.97 mmol·g⁻¹·h⁻¹).
• Performance matched or surpassed noble-metal-modified BiOI systems.
• Demonstrated enhanced piezoelectric polarization, narrowed bandgap, and improved charge migration.

Conclusions:

• Structural engineering by sulfur substitution effectively enhances piezocatalytic performance.
• This noble-metal-free strategy offers an economical route to advanced piezocatalysts.
• The developed method advances sustainable hydrogen production and energy conversion technologies.