Experimental and Density Functional Theory Simulation Research on PdO-SnO₂ Nanosheet Ethanol Gas Sensors

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Tin dioxide (SnO2) is a widely studied semiconductor material for gas sensors.
• Improving the sensitivity and selectivity of SnO2-based sensors remains a key research objective.
• Heterostructures offer potential for enhanced material properties and functionalities.

Purpose of the Study:

• To synthesize and characterize pure SnO2 and PdO-SnO2 nanosheet materials.
• To investigate the ethanol sensing performance of the prepared materials.
• To elucidate the gas-sensing mechanism of PdO-SnO2 using DFT calculations.

Main Methods:

• Hydrothermal synthesis for material preparation.
• Characterization using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS).
• Gas sensing measurements and Density Functional Theory (DFT) calculations.

Main Results:

• Two-dimensional nanosheet morphology was observed for both SnO2 and PdO-SnO2.
• Formation of PdO-SnO2 heterostructures was confirmed.
• The PdO-SnO2 sensor exhibited superior ethanol sensing performance compared to pure SnO2, attributed to the nanosheet structure, heterojunction effects, and PdO catalysis.

Conclusions:

• The PdO-SnO2 heterostructure demonstrates enhanced ethanol sensing capabilities.
• DFT calculations reveal that PdO improves ethanol reducibility, adsorption, and increases active sites, leading to a synergistic sensing effect.
• The study provides a comprehensive understanding of the enhanced gas-sensing mechanism in PdO-SnO2 materials.