Study of photodegradation performance and ability of lead removal of green synthesised maghemite nanoparticles

Today, water pollutants such as heavy metals and dyes are serious dangers to nature. Metals such as lead, chromium, mercury, and arsenic are examples of heavy metals which are toxic to living things, even sometimes at the lowest concentrations. Magnetic nanoparticles are considerable compounds because of their advantages such as high efficiency, fast recovery capability, high surface area, easy transportation, and inexpensiveness. We presented an easy and eco-friendly method for the synthesis of iron oxide nanoparticles using Ziziphus jujuba extract. In order to determine the physical, chemical and optical properties of the synthesised samples, Fourier-transform infrared (FT-IR), powder X-ray diffraction (PXRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and Raman analyses were deployed. The PXRD results showed that the synthesised nanoparticles have a maghemite form of (gamma-Fe2O3). The results showed that the synthesised nanoparticles were capable of removing 96% of lead at pH = 7 and 1 mg/L loading of nanoparticles. Adsorption isotherms of lead on nanoparticles as adsorbents were determined based on Freundlich and Langmuir adsorption isotherm models. The results showed that the best model of adsorption isotherm was Langmuir model. The photocatalytic activity of gamma-Fe2O3 NPs was studied on methylene blue (MB) dye; as a result, MB at pH = 7 and 1 gr dosage of gamma-Fe2O3 had the highest removal percentage (92.8%) during 160 minutes using gamma-Fe2O3 which calcined at 400 degrees C. The reusability results showed that after four cycles of using the gamma-Fe2O3-400, the obtained degradation of methylene blue was about 87.1%. Therefore, synthesised gamma-Fe2O3 NPs can be a good alternative for removing heavy metals and industrial dyes from contaminated waters.