Morphology control and photocatalytic characterization of WO3 nanofiber bundles

The design and fabrication of semiconductor photocatalysts have attracted much attention. Herein, the effect of pH value and soluble salt additives on crystal structure, morphology and photocatalytic properties of WO3 was investigated in detail. It was found that the phase structure of WO3 changed from monoclinic to hexagonal phase when pH value of the solution increased. The ultraviolet-visible absorption spectra show that the monoclinic and hexagonal WO3 had absorbance from 600 nm to the ultraviolet-visible region. Hexagonal WO3 with nanofiber bundle morphology was successfully synthesized through Na2SO4 and Zn(CH3COO)(2)center dot 2H(2)O-assisted hydrothermal method when pH value was 0.8. It exhibits the highest photocatalytic efficiency and better than that of cubic-shaped monoclinic WO3. The shuttle-like hexagonal WO3 prepared at pH 1.4 gives much lower activity. The morphology is a decisive parameter for the photocatalytic properties of WO3. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.