Zn-doped SnO₂ nanoparticles for ethanol vapor sensor: a combined experimental and first-principles study

Zn-doped SnO2 nanoparticles were synthesized by hydrothermal method, the morphological features were revealed by SEM and TEM, the chemical component and valence state were investigated by XRD and XPS. The gas-sensitive performance of Zn-doped SnO2 nanoparticles was tested, and the results showed that the doping of Zn elements could improve the gas-sensitive performance of the sensor, especially the 4wt% Zn-doped SnO2 exhibited higher sensitivity, lower operating temperature, and greater stability. The adsorption energy, energy band structure and density of states of ethanol molecules on pristine SnO2 and Zn-doped SnO2 crystal face were calculated through density functional theory (DFT) to explore the possibility that the improved sensing performance of Zn-doped SnO2 nanoparticles could be attributed to the generation of Schottky junctions and the reduction of adsorption energy.