Growth of ZnFe2O4 nanosheets on reduced graphene oxide with enhanced ethanol sensing properties

The design and synthesis of materials with unique hierarchical structure has important scientific and practical significance in improving their sensing properties. Herein, ZnFe2O4 nanoparticles assembled nanosheets (ZnFe2O4NSs) grown on reduced graphene oxide (RGO) was creatively constructed via a simple and fast microwave-assisted solvothermal method. RGO played the role as ground for the growth of ZnFe2O4NSs, and the growing process was investigated by a series of irradiation time dependent experiments. Finally, the gas sensing properties for the as-prepared ZnFe2O4NSs/RGO composites were evaluated. The integration of RGO was found to increase the selectivity of ZnFe2O4 to ethanol. It was found that the ZnFe2O4NSs/RGO composite with an irradiation time of 4 h (ZnFe2O4NSs/RGO 4 h) based sensor showed better ethanol sensing performance than that of sensors based on ZnFe2O4NSs assembled sphere without RGO, ZnFe2O4 nanoparticles and ZnFe2O4NSs/RGO composites with other irradiation time, respectively. ZnFe2O4NSs/RGO 4 h based sensors showed good stability and satisfied response to ethanol ranging from 0.1 ppm to 100 ppm at 210℃. The high response was attributed to its unique architecture, the integration of RGO and the formation of heterojunction between RGO and ZnFe2O4.