Self-powered zinc-air battery-driven NO₂ gas sensor enabled by multiple grain boundary-engineered CeO₂

Area of Science:

• Materials Science
• Environmental Science
• Sensor Technology

Background:

• Real-time nitrogen dioxide (NO₂) monitoring is vital for public health and environmental safety.
• Conventional gas sensors often require external power and struggle with high-temperature performance.
• Limitations in current NO₂ sensors necessitate the development of advanced, self-powered alternatives.

Purpose of the Study:

• To develop a self-powered gas sensor for real-time, room-temperature nitrogen dioxide (NO₂) detection.
• To engineer cerium dioxide (CeO₂) with multiple grain boundaries (MGB-CeO₂) for enhanced gas sensing capabilities.
• To investigate the performance of a zinc-air battery-driven NO₂ sensor utilizing MGB-CeO₂.

Main Methods:

• Fabrication of a self-powered gas sensor using a zinc-air battery and a multiple grain boundary-engineered CeO₂ (MGB-CeO₂) air cathode.
• Characterization of MGB-CeO₂ and comparison with nanorod CeO₂ (NR-CeO₂) in terms of NO₂ response and kinetics.
• Utilized Density Functional Theory (DFT) calculations to understand NO₂ adsorption mechanisms on MGB-CeO₂.

Main Results:

• The MGB-CeO₂ sensor demonstrated a 3.5-fold higher response (21.2% to 10 ppm NO₂) compared to NR-CeO₂.
• Achieved significantly shorter response and recovery times for NO₂ detection with the MGB-CeO₂ sensor.
• DFT calculations confirmed enhanced NO₂ adsorption on the defect-rich MGB-CeO₂ structure.

Conclusions:

• The MGB-CeO₂ based self-powered sensor exhibits superior performance, including high selectivity, low detection limits, and excellent long-term stability.
• The engineered grain boundaries in MGB-CeO₂ effectively promote NO₂ adsorption and charge transfer for improved sensing.
• This research presents a promising strategy for developing practical, self-powered gas sensors for environmental monitoring.