Smart adsorbent frameworks enabling high-efficiency pharmaceutical degradation via adsorption

Abstract

Pharmaceutical residues are increasingly detected in aquatic systems and present ecological and human health concerns due to their biological activity, structural complexity, and limited biodegradability. Poor removal via conventional wastewater treatment processes drives the development of smart adsorbents that offer tailored chemistry and stimuli-responsive behavior to selectively capture and degrade pharmaceuticals. This review summarizes recent advances in functionalized carbons, stimuli-responsive polymers, metal–organic frameworks, magnetic composites, and hybrid nanozymes that interact with pharmaceuticals through π–π stacking, electrostatic attraction, hydrogen bonding, and metal–ligand coordination. Special attention is paid to how surface functionalities, pore architectures, and pH-dependent speciation govern adsorption kinetics, isotherms, and selectivity. Coupling adsorption with catalytic degradation processes is highlighted as a synergistic strategy that can enable in situ transformation of adsorbed pharmaceuticals into less toxic products, overcoming drawbacks associated with adsorption-only systems, such as Fenton, photo-Fenton, or peroxymonosulphate activation. Key structure–property relationships, performance descriptors, and recyclability considerations are discussed in establishing a unified smart adsorbent design framework. Finally, critical knowledge gaps and future opportunities are identified, including scalable synthesis, selectivity tuning, regeneration, and integration into continuous treatment systems. This review offers guidelines for the rational development of next-generation smart adsorbents for efficient and sustainable removal of pharmaceutical pollutants.