Room-temperature H₂S Gas Sensor Based on Au-doped ZnFe₂O₄ Yolk-shell Microspheres

Room-temperature type H₂S sensing devices that use Au-doped ZnFe₂O₄ yolk-shell microspheres as the active material have been fabricated using a solvothermal method as well as subsequent annealing and a chemical etching process. The samples are characterized using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). The results demonstrate that the doping of Au does not change the spinel structure of the products, which were yolk-shell microspheres, while the particle size varied with the Au doping concentration. Also, the as-fabricated sensor device exhibited excellent selectivity toward H₂S gas at the room temperature; the gas-sensing property of 2 wt% Au-doped ZnFe₂O₄ microspheres was the best. The Au-doped ZnFe₂O₄ yolk-shell microspheres can be promising as a sensing material for H₂S gas detecting at room temperature.