Chlorobenzene sensor based on Pt-decorated porous single-crystalline ZnO nanosheets

Detection of chlorobenzene is a challenge for metal oxide gas sensors because of its stable molecule structure. In this work, Pt-decorated porous single-crystalline ZnO nanosheets (PSC ZnO NSs) were successfully synthesized via a one-pot hydrothermal method followed by a liquid phase reduction process. The morphology and structure of the as-prepared sample were well characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectrum (EDS) and ICP-MS analysis. From gas-sensing test, it can be found that the decoration of Pt nanoparticles largely enhanced the sensing performance of the PSC ZnO NSs. The Pt-decorated PSC ZnO NSs showed good response to low concentrations of chlorobenzene from 10 to 500 ppb. In contrast, the Au and Ag-decorated PSC ZnO NSs had still no response to 500 ppb of chlorobenzene. The enhancement sensing mechanism of Pt nanoparticle decoration has also been discussed in detail.