High-Sensitive Ammonia Sensors Based on Tin Monoxide Nanoshells.

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Ammonia (NH₃) is a harmful gas contaminant with implications for environmental protection and human health.
• Detecting low concentrations (≤50 ppm) of ammonia at room temperature remains challenging with conventional methods.
• Tin monoxide (SnO) offers a promising alternative due to its low cost, environmental friendliness, and stability.

Purpose of the Study:

• To fabricate highly sensitive ammonia sensors using self-assembly SnO nanoshells.
• To evaluate the performance of these sensors in detecting varying concentrations of ammonia.
• To explore the structural advantages of nanoshells for enhanced gas sensing.

Main Methods:

• Fabrication of SnO nanoshells via a solution method.
• Annealing the fabricated nanoshells at 300 °C for 1 hour.
• Testing sensor response to ammonia concentrations ranging from 5 ppm to 200 ppm.

Main Results:

• Sensors exhibited significant responses: 313% (5 ppm) to 3757% (200 ppm) (∆G/G).
• The nanoshell structure, with its large surface area, effectively absorbs ammonia molecules, enhancing sensitivity.
• SnO nanoshells demonstrated higher oxygen vacancy densities, contributing to superior performance and selectivity.

Conclusions:

• Self-assembly SnO nanoshells provide a highly sensitive platform for ammonia detection.
• The unique nanoshell structure and high oxygen vacancy density are key to the sensor's performance.
• This work offers a valuable reference for IV-VI metal monoxides in gas sensor applications.