Visible-light photocatalytic degradation of glyphosate over BiVO4 prepared by different co-precipitation methods

Visible-light-driven bismuth vanadate (BiVO4) photocatalysts were prepared by the co-precipitation method. The BiVO4 samples were characterized using X-ray diffraction, UV-visible diffuse reflectance, electrochemical impedance spectroscopy (EIS), photocurrent, and as well as electron microscopy (SEM, TEM). The photocatalytic activity of the as-prepared BiVO4 samples was tested through the photocatalytic oxidation of glyphosate under visible light irradiation. The dark yellow amorphous BiVO4 powder was prepared by the HAc method after drying at 70 degrees C, but the bright yellow monoclinic BiVO4 was obtained after keeping at room temperature in the air for several days. The dependence of the room temperature crystallization on moisture can explain the low crystallization temperature found in this work. The BiVO4 sample calcined at 400 degrees C by the HAc method showed the highest photocatalytic activity for glyphosate degradation under visible light irradiation because of its high charge separation efficiency proven by EIS and photocurrent. (C) 2016 Elsevier Ltd. All rights reserved.