The Effect of Solvent on the Synthesis of BiVO₄ Using Solvothermal Method and Their Photocatalytic Activity Under Visible Light Irradiation

A monoclinic-tetragonal heterostructure of BiVO₄ was successfully synthesized by performing a solvothermal method using different molar ratio of EGME/H₂O as mixed solvents. The phase structure and morphology of as-prepared BiVO₄ samples were characterized by Raman spectroscopy, XRD, SEM and DRS. We have also investigated the photocatalytic activity of these materials for the decomposition of Rhodamine B under visible light irradiation. When BiVO₄ was synthesized using a mixture of EGME and H₂O solvents (EGME/H₂O volume ratio varied from 70/10 to 10/70), XRD pattern showed the coexistence of monoclinic and tetragonal phase. From the XRD, Raman spectroscopy and SEM results, the monoclinic-tetragonal heterostructure of BiVO₄ samples prepared using different volume ratios of EGME/H₂O exhibited different morphologies and crystal structure. The BiVO₄ catalyst, which was prepared when the volume ratio of EGME/water was set at 40/40, showed the highest photocatalytic activity in the photodegradation of Rhodamine B under visible light.