ZIF-71-Coated CuO:Al with Enhanced Gas-Sensing Performance for n‑Butanol and Hydrogen

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Metal-organic frameworks (MOFs) offer tunable porosity and structural flexibility, making them promising for gas-sensing applications.
• Combining MOFs with inorganic semiconductors can create hybrid materials with synergistic properties for enhanced sensor performance.
• Zeolitic imidazolate framework (ZIF)-71 is a type of MOF with potential for gas adsorption and detection.

Purpose of the Study:

• To develop and characterize novel hybrid gas sensors by coating Al-doped CuO (CuO:Al) with ZIF-71.
• To investigate the structural, morphological, and chemical properties of the fabricated ZIF-71/CuO:Al hybrid materials.
• To evaluate the gas-sensing performance, including sensitivity, selectivity, repeatability, and durability, towards n-butanol and hydrogen gas.

Main Methods:

• Chemical solution approach for synthesizing CuO:Al films.
• Coating CuO:Al films with ZIF-71 nanoparticles.
• Structural and surface analysis using XRD, SEM, XPS, and Raman spectroscopy.
• Porosity assessment via N2 adsorption-desorption isotherms.
• Gas-sensing measurements at various temperatures and intervals.
• Thermal stability evaluation using thermogravimetric analysis.

Main Results:

• Highly crystalline CuO:Al films with well-distributed ZIF-71 nanoparticles were successfully fabricated.
• The ZIF-71/CuO:Al hybrid sensors demonstrated enhanced response to n-butanol (11% at 200 °C) and hydrogen gas (61% at 250 °C).
• The sensors exhibited good repeatability, durability, and humidity tolerance, with performance improving over time due to thermal exposure.
• N2 adsorption-desorption isotherms confirmed the microporosity and pore size distribution of ZIF-71 nanoparticles.

Conclusions:

• The MOF-ZIF-71-coated CuO:Al hybrid sensors show significant potential for selective, humidity-tolerant, and stable detection of n-butanol and hydrogen gas.
• The synergistic interaction at the ZIF-71/CuO:Al interface enhances gas detection sensitivity.
• Further optimization is recommended to improve selectivity and reduce operational temperature for practical applications.