Preparation of spindle-like BiPO₄ and its photocatalytic performance

ABSTRACT

(Ionic Liquid-BiPO₄) IL-BiPO₄ was synthesized by sonochemical process at 70C using 1-methylimidazolium dehydrogenate phosphate ([Hmim] H₂PO₄) and Bi(NO₃)₃.5H₂O as raw material. A simple synthesized method of BiPO₄ was carried out with IL at moderate condition. Moreover, the ionic liquid (IL) is environmentally friendly. The IL are synthesized using 1-methylimidazolium and H₂PO₄ as raw materials. The IL also is a surface agent showing excellent performances such as low viscosity, high dispersion and good structure-direction. Moreover, IL can be reused. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis (BET), and diffuse reflectance spectroscopy. The XRD results show an increase in peak intensity for IL-BiPO₄, and diffusive reflectance spectra reveal that there is a red shift in the optical absorption, which indicates a decrease in the band gap in IL-BiPO₄. BET analytic results show that IL-BiPO₄ is three times as large special surface as Na-BiPO₄. Spindlelike IL-BiPO₄ and rod-like Na-BiPO₄ were observed by SEM and TEM. The IL-BiPO₄ exhibits excellent UV photocatalytic activity and degradation for methyl blue solution compared with Na-BiPO₄.

KEYWORDS:

• BiPO₄
• photo-catalyst
• ionic liquid

Funding

The authors acknowledge the financial support of the Natural Science Foundation of China (Project no. 21003069).