Hydrothermally engineered magnetic biochar from jackfruit leaves for sustainable Congo Red Dye removal via Fenton-like process

Abstract The synthesis of magnetic biochar (MBC) from jackfruit leaves via a hydrothermal method demonstrates an effective approach for converting agricultural waste into a valuable functional material. The resulting MBC was thoroughly characterized, revealing a mesoporous nature with a specific surface area of 6.59 m 2 /g. The presence of iron oxide nanoparticles, confirmed by XRD and XPS analyses, was homogeneously distributed within the biochar matrix, with a mean crystallite size of 31.69 nm. The high saturation magnetization of 21.11 emu/g facilitated easy separation and recovery of the catalyst post-reaction. The catalytic potential of the MBC was evaluated by degrading Congo Red dye in a Fenton-like process, achieving 80.01% degradation efficiency at an initial dye concentration of 10 mg/L. The degradation kinetics followed a second order. The synthesised MBC retained ~ 70% removal efficiency even after five cycles, demonstrating good structural stability and practical reusability. This research highlights the ability of MBC as an efficient, magnetically separable catalyst for environmental remediation, offering a sustainable solution for dye-contaminated wastewater treatment.