title: Metastable monoclinic ZnMoO4: hydrothermal synthesis, optical properties and photocatalytic performance.
abstract: Metastable monoclinic ZnMoO4 was successfully synthesized via a hydrothermal route with variation of reaction temperatures and time at pH value of 5.7. Systematic sample characterizations were carried out, including X-ray powder diffraction, scanning electron microscopy, Fourier transformed infrared spectra, UV-visible diffuse reflectance spectra, and photoluminescence spectra. The results show that all as-prepared ZnMoO4 samples were demonstrated to crystallize in a pure-phase of monoclinic wolframite structure. All samples were formed in plate-like morphology. Six IR active vibrational bands were observed in the wave number range of 400-900 cm(-1). The band gap of as-prepared ZnMoO4 was estimated to be 2.86 eV by Tauc equation. Photoluminescence measurement indicates that as-prepared ZnMoO4 exhibits a broad blue-green emission under excitation wavelength of 280 nm at room temperature. Photocatalytic activity of as-prepared ZnMoO4 was examined by monitoring the degradation of methyl orange dye in an aqueous solution under UV radiation of 365 nm. The as-prepared ZnMoO4 obtained at 180 degrees C for 40 h showed the best photocatalytic activity with completing degradation of MO in irradiation time of 120 min. Consequently, monoclinic ZnMoO4 proved to be an efficient near visible light photocatalyst.
authors.affiliation: College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010021, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Lv
authors.forename: Wenming
authors.initials: W
authors.lastname: Tong
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yiguo
authors.initials: Y
authors.lastname: Su
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Wang