Selective-detection NO at room temperature on porous ZnO nanostructure by solid-state synthesis method

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Detecting nitric oxide (NO) with high sensitivity and selectivity at room temperature presents significant challenges.
• Porous materials with high surface areas are crucial for efficient gas adsorption and detection.

Purpose of the Study:

• To develop a novel porous zinc oxide (ZnO) nanostructure for enhanced room-temperature NO detection.
• To investigate the gas-sensing properties of the fabricated ZnO-based sensor.

Main Methods:

• A rapid and simple solid-state synthesis strategy was employed using zinc acetate and oxalic acid precursors.
• Structural and morphological analyses confirmed a porous ZnO nanostructure with a large specific surface area (32.75 m² g⁻¹).
• Gas-sensing properties, including response, selectivity, humidity effects, and stability, were systematically evaluated.

Main Results:

• The ZnO sensor exhibited an outstanding response of 23.59 and a fast response time of 331 s to 40 ppm NO at room temperature.
• The sensor showed minimal sensitivity decrease (from 1.43 to 1.12) across a wide relative humidity range (17% to 80%).
• Excellent long-term stability was observed, with a relative standard deviation of 0.33% over 8 days at 5 ppm NO.

Conclusions:

• The coralline-like porous ZnO nanostructure facilitates efficient NO adsorption/desorption, enabling selective room-temperature detection.
• The fabricated ZnO gas sensor demonstrates high sensitivity, fast response, good humidity tolerance, and remarkable stability.
• The developed sensor is suitable for practical applications in NO monitoring.