MOF-Derived In₂O₃/BiVO₄ Composites for Sensitive and Trace Detection of n-C₄H₉OH

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Metal-Organic Frameworks (MOFs) are precursors for mesoporous metal oxide semiconductors (MOS).
• MOS with high surface area are crucial for advanced gas sensor applications.
• Indium Oxide (In₂O₃) and Bismuth Vanadate (BiVO₄) are promising semiconductor materials for gas sensing.

Purpose of the Study:

• To synthesize novel MOF-derived In₂O₃/BiVO₄ composites.
• To evaluate the gas-sensing performance of the In₂O₃/BiVO₄ composites for n-butanol (n-C₄H₉OH) detection.
• To understand the sensing mechanisms behind the enhanced performance.

Main Methods:

• A three-step synthesis involving solvothermal, hydrothermal, and mechanical stirring processes.
• Characterization using techniques to determine structure and morphology (e.g., SEM, TEM, XRD).
• Gas sensing measurements at various temperatures and concentrations, including first-principles calculations.

Main Results:

• Successful synthesis of MOF-derived In₂O₃/BiVO₄ composites with hollow microtube and fishbone-like structures.
• The In₂O₃/BiVO₄-2 sensor exhibited a significantly enhanced response (149.2) to 100 ppm n-C₄H₉OH at 200 °C, 7.8 times higher than pure In₂O₃.
• Achieved an ultralow theoretical detection limit (12.6 ppb) with excellent reproducibility and selectivity for n-C₄H₉OH.

Conclusions:

• MOF-derived In₂O₃/BiVO₄ composites offer superior gas-sensing properties compared to pure In₂O₃.
• The unique hierarchical structures and synergistic effects contribute to the enhanced sensitivity and selectivity.
• This work provides a new strategy for developing high-performance n-butanol gas sensors.