Green synthesis of nanocomposite based on magnetic hydroxyapatite using Falcaria vulgaris Bernh leaf extract to remove tartrazine dye from aqueous solution

[Display omitted] •A novel and effective Fe3O4@HAP@ZnO nanocomposite using Falcaria Vulgaris Bernh leaf extract were synthesized.•The effects of different variables were investigated and optimized simultaneously using a chemometric tool.•The average of removal efficiency for simultaneously removal of target ions was ≥ 98 %.•The reusability experiments show that the removal efficiency was ≥ 90 %, up to eleven removal cycles.•Nanocomposite has a remarkable capacity of 1398 (mg g−1). To mitigate the adverse impacts of water pollution, the application of nanotechnology in dye removal and by-product reduction has the potential to establish a sustainable potable water supply. For these methodologies, the materials must involve exhibit qualities such as simplicity, high efficiency, eco-friendliness, reusability, and affordability. This study presents a novel porous magnetic hydroxyapatite nanocomposite coated with zinc oxide (Fe3O4@HAP@ZnO). Initially, zinc oxide nanoparticles were generated via a green synthesis method, where a zinc nitrate solution was combined with an aqueous extract from the Falcaria Vulgaris Bernh plant, serving as a reducing and stabilizing agent. These were then coated onto the magnetic hydroxyapatite. Verification of successful nanocomposite synthesis was obtained through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray spectroscopy (EDS), vibrating-sample magnetometer (VSM), High-resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) images further substantiated these results. The synthesized nanocomposite exhibited a normal particle size distribution of approximately 89 nm. To achieve maximal decolorization efficiency, pertinent parameters were scrutinized and optimized through a detailed experimental design. Under optimal conditions, the nanocomposite's ability to decolorize tartrazine dye in an aqueous solution was evaluated. Remarkably, the highest observed efficiency approached 98 %, employing 0.07 g of the nanocomposite at 90 degrees Celsius, pH 6.4, over a span of 30 min. Further exploration of the nanocomposite's reusability revealed it could sustain an efficiency exceeding 90 % across 11 successive cycles, boasting an impressive capacity of 1398 (mgg-1).