Hydrothermal synthesis of Ni-doped hydrangea-like Bi2WO6 and the enhanced gas sensing property to n-butanol

In this work, the pure and Ni-doped Bi2WO6 are successfully synthesized by a one-step hydrothermal method. We apply the various techniques, such as X-ray diffraction (XRD), Scanning Electron Microscope (SEM),Transmission Electron Microscope (TEM), Ultraviolet–visible spectroscopy (UV–vis) and photo luminescence (PL) et al., to characterize the structure, morphology, chemical compositions, optical properties and crystal defects of the prepared samples. Compared with pure Bi2WO6 and other Ni-doped Bi2WO6, the 4 at% Ni-Bi2WO6 sensor exhibits the highest gas response (31.2), fast response-recovery characteristic, good stability and unique selectivity to 30 ppm n-butanol at 325 ℃. The enhanced gas sensing mechanism could be attributed to its unique hierarchical hydrangea-like structure, the large specific surface area, the low band gap energy, high electron separation efficiency and abundant oxygen vacancies.