Synthesis and characterization of new NaX zeolite-supported Nb, Zn, and Fe photocatalysts activated by visible radiation for application in wastewater treatment

NaX zeolite-supported Nb2O5, ZnO, and FexOy photocatalysts were synthesized with the objective of producing photocatalysts that could be activated by visible/sunlight. The photocatalysts were prepared by wet impregnation with 10% (w/w) precursor. X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to investigate the crystalline and electronic structures of the supported photocatalysts. The results obtained showed that Nb2O5 impregnation resulted in a synergistic effect with the zeolite matrix forming Nb2O5/NaX with a bandgap of 2.9 eV, which is lower than that of bulk Nb2O5 (3.2 eV). The synthesized β-FexOy (goethite) active-phase supported on NaX acted as a photocatalyst that could be activated by visible energy photons. A photocatalytically active phase was not observed for ZnO/NaX. Nb2O5- and β-FexOy-impregnated zeolite structures formed potential photocatalysts that absorb radiation with ultraviolet and visible wavelengths.