Recyclable Natural Magnetite Nanoparticles for Effective Degradation of Methylene Blue in Water under UV Light Irradiation

Among the numerous materials used for dye removal, magnetite is particularly interesting due to its ability to act as an adsorbent and a Fenton catalyst, being easily separable by application of a magnetic field and reusable. Herein, we describe a co-precipitation–based synthesis of magnetite nanoparticles (particle size = 11 nm, surface area = 147.12 m² g^–1) from iron sand and investigate their effectiveness for methylene blue (MB) degradation. The above nanoparticles could promote the decomposition of MB both in the dark (via adsorption) and under UV light irradiation (via Fenton-type degradation), exhibiting the additional advantage of recyclability. Thus, MB degradation efficiencies are 76.32, 76.08, and 68.52% for first, second, and third cycles, respectively, indicating that the prepared magnetic material is a promising recyclable catalyst for the decontamination of dye-containing wastewater. The photo Fenton reactions take to account for reproducibility of MB degradation.