Sonochemical assisted hydrothermal synthesis of pseudo-flower shaped Bismuth vanadate (BiVO) and their solar-driven water splitting application.

Bismuth vanadate (BiVO) is a well-known photocatalyst due to its lower bandgap (E) and visible electromagnetic light absorption capacity. Herein, we reported the pulse ultra-sonochemical assisted hydrothermal approach to synthesize S-BiVO. For the comparison purpose, H-BiVO is also synthesized via conventional hydrothermal approach. The surface morphology of S-BiVO through scanning electron microscope (SEM) indicates condensed microarrays (MAs) having pseudo-flower shapes. The energy dispersive X-rays (EDX) spectrum also confirmed the elemental percent composition of Bi, V and O in BiVO. X-rays diffraction (XRD) pattern further confirmed the monoclinic scheelite phase of S-BiVO. Fourier transformed infrared (FTIR) spectrum showed Bi-O and Bi-V-O vibrational bands at 1382 and 1630cm, respectively. The diffuse reflectance spectroscopy (DRS) indicated absorption edge at ∼515nm, corresponds to bandgap value (E) of 2.41eV, which is suitable range for water splitting applications. The photocurrent density from water splitting under artificial 1 SUN visible light source found at 60 and 50μA/cm for S-BiVO and H-BiVO, respectively. The stability test through chronoamperometry showed that S-BiVO was more stable than H-BiVO. It can be depicted from the growth mechanism that ultrasonication played a definite role in the overall synthesis of pseudo-flower shaped S-BiVO MAs.