A brief study on the Eriochrome Black T photodegradation kinetic by CdS/ BiVO4 coupled catalyst

The coupled CdS/BiVO4 coupled catalyst was prepared via mechanical mixing of the as-synthesized CdS and BiVO4 NPs. Samples were investigated by scanning electron microscope (SEM), X-ray diffraction diffractometer (XRD), UV-Vis diffuse reflectance spectroscope (DRS), and Furrier transformation infrared spectrophotometer (FT-IR). The average crystallite sizes for CdS, BiVO4, and CdS/BiVO4 were obtained about 5.8, 34.9, and 37.3 nm By the Scherrer formula), and about 1.7, 23.1, and 12.5 nm (by the Williamson-Hall formula), respectively. The absorption edges of 622, 529, and 571 nm corresponding to bandgap energies of 1.99, 2.24, and 2.17 eV were respectively obtained for CdS, BiVO4, and CdS/BiVO4. A boosted photocatalytic activity of the coupled system was observed in the photodegradation of EBT (Eriochrome Black T). When moles of the BiVO4 component were 3-4 times greater than CdS, the highest activity was achieved. The rate constant of 0.032 min-1 and 0.007 min-1 were respectively obtained by the absorbencies recoded for the photodegraded EBT solutions and chemical oxygen demand (COD) data obtained in the photodegraded solutions. These values correspond to t1/2-values of 21.7 min and 99 min for the degradation and mineralization of EBT molecules during the photodegradation process. Here, a cheap and straightforward mechanical method was used to prepare the binary visible-light active CdS/BiVO4 photocatalyst with satisfying charge carriers' transfer and good photocatalytic activity. Superscript/Subscript Available

Automated summary

The coupled CdS/BiVO4 catalyst was prepared via mechanical mixing, showing enhanced photocatalytic activity in the degradation of EBT. The highest activity was achieved when the moles of BiVO4 component were 3-4 times greater than CdS. The cheap and straightforward mechanical method was used to prepare the binary CdS/BiVO4 photocatalyst with satisfying charge carriers' transfer and good photocatalytic activity.