Low-Temperature Ozone Sensors Based on Yb-Doped Urchin-like Hierarchical In₂O₃ Microspheres

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Ozone (O3) is a toxic gas requiring sensitive detection.
• Developing low-temperature, high-performance ozone sensors remains a challenge.
• Indium oxide (In2O3) is a promising semiconductor material for gas sensing.

Purpose of the Study:

• To synthesize Ytterbium (Yb)-doped urchin-like hierarchical In2O3 microspheres.
• To investigate the effect of Yb doping on the ozone-sensing properties of In2O3.
• To develop a highly sensitive and stable ozone gas sensor.

Main Methods:

• One-step hydrothermal synthesis of In2O3 and Yb-doped In2O3.
• Characterization using XRD, FESEM, TEM, HRTEM, XPS, and UV-vis spectroscopy.
• Gas-sensing performance evaluation for ozone detection at low temperatures.

Main Results:

• Yb doping significantly enhanced the ozone-sensing performance of In2O3.
• The 3% Yb-doped In2O3 sensor showed a high response (approx. 1015) to 1 ppm ozone at 40 °C.
• The sensor exhibited a fast response time (172 s), good repeatability, selectivity, and long-term stability.

Conclusions:

• Yb doping modulates the electronic structure and increases oxygen vacancies in In2O3, enhancing sensing performance.
• The urchin-like hierarchical structure improves gas diffusion and interfacial reactions.
• Yb-doped In2O3 offers a promising material for developing advanced low-temperature ozone sensors.