Use of core-shell nanomaterials as potential adsorbents for fluoride remediation: Toward a sustainable ecosystem

The world today is facing a water crisis. Water and sanitation are central to sustainable development and critical for the survival of people and the planet. Among various other water contaminants, it has recognized fluoride contamination as a primary concern worldwide, posing a serious risk to human health and affecting potable water security. Core-shell adsorbents are appropriate substitutes for existing water defluoridation materials and have shown excellent efficiency due to their high adsorption capacity, easy separability, reusability, excellent magnetic properties. Also, recent progress in employing core-shell-based materials has opened up many avenues for water defluoridation technologies. Although a few studies have already covered the use of core-shell as adsorbents in the remediation of various contaminants, their sole adsorptive applications regarding fluoride remediation have not been thoroughly explored yet. Therefore, for the first time, we try to cover the extensive applications of core-shell adsorbents in the field of fluoride elimination from water over the last ten years. This work gives an insight into how core-shell adsorbents are superior to conventional and non-conventional methods of defluoridation. Also, special attention is paid to the current developments and challenges of various novel core-shell adsorbents because of their significant mechanism of action. Lastly, emerging technologies and challenges faced in this area of research are discussed. [Display omitted] •Post synthetic surface modification is pivotal in enhancing adsorption capacity.•Size of the metal regulates the strength of core-shell's metal-ligand bond.•Core-shell nanomaterials open new horizon in the sensing of heavy metals.•Strong interaction between fluoride and core-shells results in effective adsorption.