Shape-controlled fabrication and enhanced gas sensing properties of uniform sphere-like ZnFe2O4 hierarchical architectures

Abstract

Spinel-typed ZnFe2O4 nanostructures have attracted much attention owing to their remarkable properties and display promising potential in gas sensors. In this work, spinel ZnFe2O4 compounds with different 3-D sphere-like morphologies, namely faceted microspheres and solid microspheres, were successfully synthesized by employing a facile template-free solvothermal process coupled with a post annealing treatment. The chemical composition, morphology and surface features of the as-obtained products were characterized well by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller analysis technique. Considering the favorable structures of products, gas sensors were fabricated to explore their sensing performance. Impressively, the detailed gas tests indicate that the faceted ZnFe2O4 microspheres have a marked kinetic response speed and fascinating selectivity toward some volatile organic pollutants, especially to ethanol, at operating temperature of 180°C. As such, we conclude that the faceted ZnFe2O4 microspheres will be a promising candidate as a high-performance gas sensing material.