Biosynthesis of BiVO4 nanorods using Callistemon viminalis extracts: Photocatalytic degradation of methylene blue

This contribution reports on the biosynthesis of the n-type Bismuth vanadate (BiVO4) nanorods prepared via the use of aqueous extracts of Callistemon viminalis as an effective chelating agent. To ascertain the formation of crystalline and pure BiVO4 nanorods, various surface & interface characterization were performed on annealed BiVO4 powders. X-Ray Diffraction analysis showed that the BiVO4 nanorods obtained after annealing at 500 degrees C, were of high purity and polycrystalline in nature. The morphological analysis revealed that the basal & longitudinal dimensions of the obtained BiVO4 nanorods ranged from 350 to 450 nm and 1.2-2 mu m, respectively. The effect of the annealed BiVO4 nanorods on the photocatalytic degradation of methylene blue (MB), a model pollutant, was evaluated with obtained results suggesting that the degradation of Methylene Blue in the presence of BiVO4 nanorods occurs at an efficiency of 82% under Solar Visible after 5 h, at room temperature. These results show that bio-synthesized BiVO4 prepared using plant extracts of Callistemon viminalis could be a promising method for the synthesis of functional nanomaterials that find use as photocatalysts. (C) 2019 Elsevier Ltd. All rights reserved.