Coconut Fiber Decorated with Bismuth Vanadate for Enhanced Photocatalytic Activity

Bismuth vanadate/coconut fiber (BiVO₄/CF) composites were synthesized by coprecipitation and calcination methods. All catalysts used in this work were prepared by a simple coprecipitation method and fully characterized by means of XRD, SEM-EDS, PL, BET N₂ adsorption, zeta potential, and UV-vis DRS. Degradation of indigo carmine (IC) under visible light irradiation was tracked by the UV-vis technique. It was documented that XRD patterns of BiVO₄ and BiVO₄/CF samples retained the monoclinic structure. From SEM, the CF sheets were visualized, covering the surface of BiVO₄ particles. The specific surface area of the synthesized catalysts increased from 1.77 to 24.82 m²/g. The shift of absorption edge to a longer wavelength corresponded to a decrease in band gap energy from 2.3 to 2.2 eV. The photocatalytic degradation rate of the BiVO₄/CF composite was five times higher than that of pristine BiVO₄. Moreover, the photocatalyst can be separated and recycled with little change after the third times recycling. The improved activity of the composite resulted from the combination of the adsorption performance of the substrate CF and the photocatalytic activity of BiVO₄. In addition, the position of the specific mechanism could occur via both the active species of superoxide radical and hydroxyl radical.