Facile fabrication of g-C3N4 supported Fe3O4 nanoparticles/ZnO nanorods: A superlative visible light responsive architecture for express degradation of pantoprazole

Fe3O4/ZnO nanorods were first fabricated through a facile chemical route and then anchored on g-C3N4 sheets. X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, elemental mapping, X-ray photoelectron spectroscopy (XPS), UV-visible (UV-vis) spectrophotometry and photoluminescence (PL) techniques were carried out for the evaluation of the morphology, structure, composition, and optical properties of the nanocomposite thus constructed. Further, magnetic properties of the nanocomposite were evaluated using vibrating sample magnetometer (VSM) techniques. All tests confirmed the formation of heterostructured Fe3O4 nanoparticles/ZnO nanorods that were anchored on g-C3N4 sheets. Photoluminescence results revealed remarkable separation of photo-generated charged carriers and their delayed recombination in the ternary nanocomposite. The hybrid catalyst showed remarkable photocatalytic activity under visible light, as evident from the efficient degradation of pantoprazole, a pharmaceutical drug widely known as a recalcitrant organic water pollutant. The effect of parameters such as catalyst dose, initial concentration, pH, and contact time was studied and a detailed investigation into their corresponding kinetics was made. The photodegradation efficiency of the ternary nanocomposite could be attributed to the synergistic interactions between ZnO, Fe3O4 and g-C3N4. A degradation efficiency of 97.09% with a TOC removal of 85.45% was achieved within 90 min with a remarkable pseudo-first order degradation rate constant of 0.04330 min(-1). The incorporation of Fe3O4 expectedly facilitated the ready recovery of catalyst. Furthermore, the degradation rate displayed fair consistency up to 4 cycles. The work thus offers a cost-efficient strategy for tackling organic water pollutants.