Spinel ZnFe2O4 nanoparticle-decorated rod-like ZnO nanoheterostructures for enhanced gas sensing performances

Abstract

Spinel ZnFe₂O₄ nanoparticle-decorated rod-like ZnO nanoheterostructures have been successfully synthesized via a facile, one-pot and environmentally friendly low-temperature hydrothermal strategy. The structural and composition information about the obtained ZnFe₂O₄/ZnO nanoheterostructures has been examined by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Considering the promising gas sensor applications, we have investigated the gas sensing performances of the ZnFe₂O₄/ZnO nanoheterostructures for detecting several common reducing volatile organic pollutants including n-butanol, ethanol, acetone, methanol and formaldehyde. The gas sensing measurement results demonstrated that the fabricated ZnFe₂O₄/ZnO nanoheterostructure sensor displayed high response, quick response/recovery characteristics, and good reproducibility for these tested gases, and good selectivity for n-butanol, revealing its promising application as a gas sensor for detecting these polluting gases and selectively detecting n-butanol. It is interesting to find that the ZnFe₂O₄/ZnO nanoheterostructure sensor exhibited much enhanced gas sensing performances compared with the pristine ZnO sensor. The excellent gas sensing performances can be attributed to the unique 1D rod-like nanostructures and the formation of the heterojunctions at the ZnFe₂O₄/ZnO interfaces. It is expected that the current synthesis methodology can be extended to fabricate other rod-like ZnO based nanoheterostructures, such as CuO/ZnO and SnO₂/ZnO, for a wide application range including chemical sensors, photocatalysis and optical devices.