Hydrothermal synthesis and characterization of Ag2O/CeO2 modified 3D flower-like ZnO as the N-butanol-sensing

Abstract

In this work, Ag2O/CeO2 modified 3D flower-like ZnO have been synthesized by a novel SDBS−PEG assisted hydrothermal route and the gas sensor fabricated from this material has prominent performance to n-butanol vapor. The 3D microporous ZnO flower-like structures with excellent adsorption property have been indicated by the images of field-emission electron microscopy (FESEM) and the analysis results of Brunauer-Emmett-Teller method (BET). The uniformly dispersed pure phase with high crystallinity existed has been verified by the X-ray diffraction (XRD) patterns combined with the Energy Dispersive Spectrometer (EDS) analysis. The X-ray photoelectron spectroscopy (XPS) further confirmed the co-existence of Ce3+/Ce4+, Ag/Ag+. Meanwhile, the gas sensor of the Ag2O/CeO2 modified ZnO (3 at% Ce, 1 at% Ag) showed the highest response to n-butanol of 100 ppm is 254 at 160 °C. It also exhibits good repeatability and satisfactory selectivity to target gases at 160 °C during gas sensing test. Even more importantly, a particular synergistic enhancement mechanism of Ag2O/CeO2 modified ZnO as the n-butanol-sensing has been explained. Employing SDBS/PEG micelles as structure-directing agent, the process of assembling 2D nanosheets into the 3D microporous ZnO flower-like structures has been discussed.