Gd³⁺ doped BiVO₄ and visible light-emitting diodes (LED) for photocatalytic decomposition of bisphenol A, bisphenol S and bisphenol AF in water

The photocatalytic efficiency of BiVO₄ was enhanced through rare-earth doping (Gd³⁺). The effect of different concentrations of Gd³⁺ was evaluated through the decomposition of bisphenol A in water. To better understand the photocatalytic properties of the synthesized photocatalysts, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET) method were applied. It was found that 4% of Gd³⁺ in molar mass showed the best photocatalytic efficiency. Decomposition of bisphenol A, bisphenol S, and bisphenol AF was studied using the photocatalyst with the optimal concentration of Gd³⁺, reaching decomposition percentages up to 77.02% ± 2.16, 44.36% ± 2.74%, and 74.11% ± 5.09, respectively after three hours reaction. Reactive species were identified by scavenging tests and additionally, kinetic studies were performed. A decomposition pathway was proposed for the three studied pollutants. The synthesized Gd³⁺ doped BiVO₄ photocatalysts demonstrated to be a promising alternative for the efficient degradation of disrupting endocrine compounds such as bisphenol A analogs present in water using LED visible light as an eco-friendly irradiation source.