The effect of potassium chloride on BiVO₄ morphology and photocatalysis

Abstract

The monoclinic BiVO₄ was synthesized via a facile one-pot hydrothermal synthesis. KCl concentration in the precursor greatly influences the crystal growth, morphology, and absorption properties of BiVO₄ attributed to the effect of Clˉ ions on the formation of BiOCl intermediate and preferential growth of BiVO₄ crystals along {010} planes. The photocatalytic property of BiVO4 is accordingly altered based on the KCl content. The “shuriken-like” BiVO₄ prepared with 3 ​mmol of KCl exhibits the highest photocatalytic activity among our samples. Its photocatalytic rhodamine B degradation efficiency could reach 94.7% after 4 ​h of visible-light irradiation. The degradation efficiency only decreased to 90.8% after four runs of 4 h irradiation. The photodegradation rate with the shuriken-like BiVO₄ is around 2.3 times higher than that with the rod-like BiVO₄ prepared without KCl, owing to its highest relative intensity ratio of (040) to plane, which maximizes the exposed active {010} facets of BiVO₄.