Enhanced Formaldehyde Gas Sensor based on Au-loaded ZnSnO 3 Microspheres Nanocomposites

ZnSnO 3 microspheres was compounded by hydrothermal method with sodium alginate (SA) as a crystal growth modifier, and the Au nanoparticles were decorated on the surface of ZnSnO 3 microspheres by simple solution method and heat treatment process. The structure and morphology of the prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Under ultraviolet (UV) irradiation, the 0.2wt% Au/ZnSnO 3 @4g/L SA sensor could detect HCHO and reached a good response of 18.8 at 20 ppm, which was three times higher than the ZnSnO 3 in the absence of Au. This sensor also performed an outstanding linearity within 5–20 ppm HCHO and satisfied repeatability. Moreover, the possible mechanism of the influence of Au on gas sensitivity is also proposed.