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 Bi 2 WO 6 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 Bi 2 WO 6 and other Ni-doped Bi 2 WO 6 , the 4 at% Ni-Bi 2 WO 6 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. We have fabricated the pure Bi 2 WO 6 and Ni-doped Bi 2 WO 6 successfully. The as-fabricated 4 at% Ni-doped Bi 2 WO 6 gas sensor shows superior gas-sensing performance toward n-butanol. [Display omitted] • The pure and Ni-doped Bi 2 WO 6 were successfully synthesized by hydrothermal method and the 4 at% Ni-Bi 2 WO 6 exhibits hydrangea-like morphology with hierarchical structures. • The Ni-doped Bi 2 WO 6 gas sensor presented a largely enhanced gas sensing properties to n-butanol. • The 4 at% Ni-doped Bi 2 WO 6 gas sensor showed excellent gas sensing properties to n-butanol. • The introducing Ni into Bi 2 WO 6 can increase oxygen vacancies and improve high electron-hole pairs separation efficiency. [ABSTRACT FROM AUTHOR]