Ternary g-C3N4/Ag/BiVO4 nanocomposite: Fabrication and implementation to remove organic pollutants

Abstract

To remove toxins from water bodies, photocatalytic pollutant degradation seems efficient. Presently, a ternary g-C 3 N 4 /Ag/BiVO 4 photocatalyst has been fabricated, where Ag nanoparticles act as electron shuttle and Ag/BiVO 4 have been fixated on the surface of g-C 3 N 4 . To study the catalyst, XRD, HRTEM-EDX, FESEM along with EDS, elemental mapping, PL, UV–Vis DRS were performed, suggesting crystalline plate-like nanostructures with a low bandgap energy (2.41eV) and recombination rate. The surface area analysis via BET N 2 adsorption–desorption validated a high surface area ( ∼ 6.68 m 2 /g) for the composite comprising mesopores (46.13 nm). The photocatalyst degraded methylene blue (MB), a model dye, and fipronil (FIP), a model colorless insecticide with ∼ 94% and ∼ 74% efficiency at high rate constants (0.083 and 0.0167 min −1 , respectively). The heightened activity of the ternary composite was owned to greater electron–hole charge separation and the presence of hetero-junctions while maintaining enough redox properties. The pH and catalyst concentrations were varied and examined, 94.57% and 72.56% efficiency for MB and FIP at pH 8 and 4 with catalyst concentrations 0.13 and 0.06 g/L, respectively. The trapping experiments revealed the eloquent role played by • OH (hydroxyl radical), O 2 • — (superoxide radical), and h + (holes) in the pollutant degradation. To affirm the durability of the ternary composite, a reusability test was performed for 4 successive cycles (89.85% and 69.87% efficiency for MB and FIP). XRD analysis explicated its stability after photodegradation. The ternary composite can be considered as a promising photocatalyst owing to its feasible design and efficiency in visible light for toxin deposition. • Z-scheme ternary g-C 3 N 4 /Ag/BiVO 4 nanocomposite fabricated via hydrothermal method. • Ag was loaded on BiVO 4 via illumination under visible light. • Ultrasonication technique employed to stack Ag-loaded BiVO 4 onto g-C 3 N 4 plates. • Visible-light degradation of MB dye and insecticide FIP was investigated. • Photodegradation efficacies of ∼ 94% and 74% for MB and FIP, respectively.