Sulfur dioxide sensing properties of MOF-derived ZnFe2O4 functionalized with reduced graphene oxide at room temperature

In this paper, ZnFe2O4 nanorods were prepared using Zn/Fe metal organic framework (MOF) as precursors, and ZnFe2O4/reduced graphene oxide (rGO) was prepared by hydrothermal method. The morphology and composition of the ZnFe2O4/rGO nanocomposite were characterized, and the results showed that the MOF-derived ZnFe2O4 nanorods are uniformly modified on the surface of rGO. The ZnFe2O4/rGO nanocomposite exhibits better SO2 gas sensing performance than the single ZnFe2O4 nanorods at room temperature. The sensing characteristics of single ZnFe2O4 film sensor, single rGO film sensor and ZnFe2O4/rGO composite film sensor at SO2 gas concentration (1 × 10−6–100 × 10−6) were tested. The response of ZnFe2O4/rGO composite sensor can reach 18.32% at room temperature. Compared with single ZnFe2O4 and rGO film sensors, the ZnFe2O4/rGO composite sensor has better transient response, good sensitivity and selectivity. In this work, the improvement of the sensor performance is not only due to the p–n heterostructure between ZnFe2O4 nanorods and rGO nanosheets, but also to the excellent electrical properties of rGO. It provides a new idea for the detection of SO2 at room temperature.