From waste to intelligent biochar nanocomposites: unifying advanced oxidation processes, structure-reactivity-guided...

Pesticide residues remain a major threat to ecosystems and food security, warranting novel remediation strategies that extend beyond conventional approaches. Biochar-based photocatalytic nanocomposites serve as a transformative platform, repurposing waste biomass into high-performance catalysts that combine waste valorization, exceptional charge dynamics and tunable reactivity. This review integrates innovations in advanced oxidation processes (AOPs), including hydroxyl radical pathways, UV/H₂O₂ systems, and Fenton, photo-Fenton and ozone-based strategies, with biochar-supported metal oxide photocatalysts (TiO₂@biochar, CuO@biochar, FeO _x @biochar, and ZnO@biochar), redox-tunable hybrids, nano zero-valent metals and single-atom catalysts. We discuss pesticide structure-reactivity frameworks that guide degradation efficiency and highlight data-driven predictive modeling approaches as a paradigm shift for the rational nanocomposite design. By linking mechanistic insights with computational intelligence, this perspective lays the groundwork for scalable and sustainable pesticide remediation.