Abstract
Novel visible
light photochromic silica sol gel hybrid film was successfully synthesized by blending the composite of bismuth
vanadate (BiVO 4 ) and phosphotungst ic acid (PWA). The crystal phase, microstructure, photochromic properties and
mechanism were investigated via X raydiffraction ( XRD ), transmission electron microscope (TEM), Fourier transform infrared
spectroscopy (FT IR), ultraviolet visible (UV Vis) spec tra and X ray photoelectron spectroscopy (XPS). XRD pattern
confirmed the existence of BiVO 4 and PWA in SiO 2 sol gel composite films. FT IR results indicated that the basic structure of
BiVO 4 nanopartical and the Keggin geometry of PWA were not damaged in the process of compositing and there was a
strong interaction between BiVO 4 and PWA. TEM images showed that PWA with the homogeneous spherical morphology
well dispersed in the surface of BiVO 4 and a part of PWA embedded into BiVO 4 hybrid film. Irradiated w ith visible light, the
composite film turned to blue from colorless. The hybrid film showed reversible photochromism in the presence of oxygen.
According to XPS results, PWA accepted electrons from BiVO 4 and the photo reduction process was concerned with
p hotogenerated electron transfer mechanism..
Keywords
Silica sol gel B ismuth vanadate Polyoxometalates Hybrid film Visible light photochromism.
Citation
ZONG-LAI LIU, GUO-PENG ZHU, ZHENG-YI WANG, LI-CHEN ZHAO, BO DONG, YONG-HE DONG, WEI FENG, Novel hybrid silica thin film based on bismuth vanadate and polyoxometalates system: visible-light photochromic behavior and mechanism, Optoelectronics and Advanced Materials - Rapid Communications, 13, 5-6, May-June 2019, pp.320-325 (2019).
Submitted at: Oct. 12, 2018
Accepted at: June 14, 2019