Harnessing nitrogen doped magnetic biochar for efficient antibiotic adsorption and degradation

Nitrogen-doped magnetic biochar (N-doped magnetic BC) has garnered significant attention as a multifunctional material for the remediation of antibiotic-contaminated water, owing to its synergistic adsorption and catalytic degradation capabilities. This review critically evaluates the transformative role of pretreatment strategies on the physicochemical attributes of biochar, focusing on nitrogen doping and chemical activation. These methodologies are complemented by post-treatment processes designed to impart synergistically optimized magnetic properties to the biochar matrix. Such modifications are pivotal in fine-tuning the material's characteristics, including surface area, pore architecture, and active site configuration, thereby enhancing its adsorption efficiency and catalytic performance. Advanced characterization techniques, such as electron microscopy, X-ray diffraction, and various spectroscopic modalities, provide comprehensive insights into the structural, surface, and magnetic properties of nitrogen-doped magnetic BC. The adsorption mechanisms are predominantly governed by π-π interactions, hydrogen bonding, and electrostatic forces, with nitrogen doping and magnetic functionalization significantly amplifying the material's selectivity and adsorption capacity. Furthermore, the catalytic degradation of antibiotics occurs via both radical and non-radical pathways, underscoring the dual functionality of the material. Notably, N-doped magnetic BC demonstrates excellent recyclability, maintaining high efficiency across multiple adsorption–desorption cycles. This highlights its potential for sustainable application. Future research directions proposed in this study emphasize advancing the eco-compatibility and scalability of N-doped magnetic BC. Computational modelling is suggested to predict and optimize the material's physicochemical properties, alongside the development of large-scale, environmentally benign synthesis techniques. These advancements aim to position N-doped magnetic BC as a cornerstone material in wastewater treatment systems.