Ppb-level unsymmetrical dimethylhydrazine detection based on In₂O₃ hollow microspheres with Nd doping

Area of Science:

• Materials Science
• Chemical Sensing
• Environmental Monitoring

Background:

• Unsymmetrical dimethylhydrazine (UDMH) is a high-energy rocket fuel with significant environmental and health risks.
• Effective monitoring devices are crucial for detecting UDMH leakage and mitigating its harmful effects.

Purpose of the Study:

• To develop a highly sensitive and selective gas sensor for detecting unsymmetrical dimethylhydrazine (UDMH).
• To investigate the effect of Neodymium (Nd) doping on the gas sensing properties of Indium Oxide (In2O3) hollow microspheres.

Main Methods:

• Fabrication of In2O3 hollow microspheres doped with varying concentrations of Nd (1.0, 3.0, 5.0 mol%) using a one-step solvothermal method.
• Gas sensing performance evaluation of the fabricated sensors towards UDMH vapor at different temperatures.
• Analysis of the structural and compositional properties influencing gas sensing behavior.

Main Results:

• The sensor based on 3.0 mol% Nd-doped In2O3 exhibited the highest response to UDMH (183.3 to 100 ppm), significantly outperforming pure In2O3 (26.8).
• The 3% Nd-In2O3 sensor demonstrated excellent selectivity, a rapid response time of 2 seconds, and an ultra-low limit of detection (LOD) of 0.28 ppb.
• Nd doping enhanced specific surface area, increased adsorbed oxygen concentration, and improved UDMH molecular adsorption capacity.

Conclusions:

• Neodymium doping significantly enhances the gas sensing performance of In2O3 hollow microspheres for UDMH detection.
• The developed Nd-doped In2O3 sensor is a promising candidate for real-time UDMH monitoring applications.
• The findings contribute to the development of advanced materials for environmental safety and industrial hygiene.