Controlled Synthesis of ZnFe2O4 Hollow Microspheres and Highly Sensitive Detection for n-Butanol Vapor

The hollow and porous features of materials could play an active role in promoting gas-sensitive performances. In this study, two types of ZnFe2O4 nanomaterial with different morphologies and microstructures were prepared. The microstructures and gas-sensitive properties of ZnFe2O4 were investigated by characterization techniques and testing systems, respectively. The results showed that the nanoparticle-assembled hollow ZnFe2O4 microspheres showed a high response to n-butanol vapor. The response of S1 (hollow microspheres) to 50 ppm n-butanol vapor reached 215 at 240 °C, which is higher than the case of S2(nanoparticles), and the response value of S1 was about 2.5 times that of S2. In addition, the response/recovery time of S1 (112 s/60 s) is also slightly shorter than that of S2 (123 s/80 s). The enhanced performance may be due to the unique microstructure providing more adsorption sites for gas adsorption and multiple channels for the reaction.