Transition metal elements-doped SnO₂ for ultrasensitive and rapid ppb-level formaldehyde sensing

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Tin dioxide (SnO2) is a semiconductor material with potential applications in gas sensing.
• Improving the sensitivity and selectivity of SnO2-based sensors is crucial for environmental monitoring.

Purpose of the Study:

• To synthesize and characterize Fe-doped and Ni-doped SnO2.
• To investigate the formaldehyde-sensing properties of pristine and doped SnO2.
• To determine the optimal doping concentration for enhanced sensing performance.

Main Methods:

• Facile hydrothermal synthesis method.
• X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and UV-Vis Diffuse Reflectance Spectroscopy (DRS) for material characterization.
• Formaldehyde gas-sensing measurements at various temperatures.

Main Results:

• Successful incorporation of Fe and Ni dopants into the SnO2 crystal structure was confirmed.
• Transition metal-doped SnO2 exhibited significantly improved formaldehyde-sensing properties compared to pristine SnO2.
• Optimal doping concentration of 4 at.% for both Fe and Ni resulted in the most effective enhancement.
• At 160 °C, 4 at.% Fe-SnO2 and 4 at.% Ni-SnO2 showed response values 2.4 and 1.4 times higher than pristine SnO2, respectively.

Conclusions:

• Fe and Ni doping effectively enhance the formaldehyde-sensing performance of SnO2.
• The improved sensing properties are attributed to changes in electronic and crystal structure, along with the catalytic effect of transition metals.
• Optimized doped SnO2 materials show promise for sensitive formaldehyde detection applications.