Water decontamination using bio-based, chemically functionalized, doped, and ionic liquid-enhanced adsorbents: review

The access to clean water is a critical issue in the context of climate change and worldwide pollution, calling for advanced methods of purification. Recent advances in materials science, nanoscience, and analytical chemistry have led to the design of novel nanoadsorbents having a unique properties, structure, and adsorption performances. In particular, research has focused on all-inclusive adsorbents which can remove different contaminants simultaneously. Here, we review the adsorption dynamics of doped, ionic liquid-enhanced, bio-based, and chemically functionalized materials. We examine their characteristics, underlying principles of adsorption, and their potential limitations in adsorbing various metal ions and xenobiotics. We found that chemical functionalization with specific organic moieties is a preferred approach for enhancing the adsorption capacities and selectivity of raw materials. Moreover, doping can also modulate the morphology, electronic structure, and surface chemistry for higher performance. Ionic liquids are promising solvents for the synthesis of stable adsorbents, owing to ionic liquid ability to pull other molecules through hydrogen bonds or electrostatic forces.