Green synthesis and characterization of Fe2O3, ZnO and TiO2 nanoparticles and searching for their potential use as biofertilizer on sunflower

Nanoparticles, thanks to their superior properties such as large surface area and high reactivity, can be an alternative to traditional fertilizers for improving nutrient uptake. Furthermore, considering that chemical and physical synthesis methods require high energy consumption and cause environmental pollution, plant-mediated green synthesis of NPs has attracted great attention since it provides eco-friendly, biocompatible, and inexpensive solutions. In this present study, plant mediated green synthesis of Iron Oxide (Fe 2 O 3 ), Zinc Oxide (ZnO) and Titanium Dioxide (TiO 2 ) nanoparticles by using Laurus nobilis leaves (bay leaves) were carried out and their structural properties were characterized by UV visible spectra, Dynamic Light Scattering (DLS), Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). UV spectrum and FTIR analysis exhibited characteristic peaks indicating the presence of the desired NPs, while DLS analysis and TEM images confirmed that synthesized particles are in nano-scale. The potential of nanoparticles as biofertilizer in agricultural uses were assessed by investigating their effects on sunflower growth in hydroponic system. TEM images of the NP applied plant tissues proved the uptake and translocation of NPs from root to leaf. Furthermore, Fe 2 O 3 , ZnO and TiO 2 NP applications on sunflower up to 5 ppm generally improved physiological growth parameters such as root length, fresh weight and leaf surface area while 20 ppm of Fe 2 O 3 and ZnO NPs application cause a significant decrease. Graphical abstract