Enumeration of research journey of MOF@hydrogel composite beads as potential adsorbents for adsorptive elimination of toxic contaminants

The elimination and immobilization of contaminants into water bodies have posed an unprecedented threat to the environment, which has significantly increased the demand for freshwater and sparked a plethora of developments toward water sustainability. Metal-organic frameworks (MOFs) have attracted significant interest among the materials being researched for water treatment as potential candidates for the liquid-phase adsorptive elimination of emerging contaminants. However, the crystalline or powdered form of MOFs severely restricts their use due to their innate fragility, poor processability, and low recoverability. Nevertheless, it is increasingly evident that efforts are being undertaken to give MOFs the ability to be shaped at the macroscopic level, which has led to the inclusion of MOFs into hydrogels to generate spherical beads of MOF@hydrogel composite in order to render them for realistic wastewater remediation. The subsequent MOF@hydrogel composite beads (MOF@HG CBs) encompass the application of MOFs in the removal of contaminants by elevating their mechanical flexibility and imparting them superior adsorption characteristics without hampering their adsorptive performance. The present review spotlights the recent advancements in the performance of MOF@HG CBs as adsorbents for the efficacious elimination of heavy metal ions, dyes, pharmaceuticals, personal care items, pesticides, rare earth elements, and organic contaminants. This review will provide basic and in-depth insight to the researchers to explore the advanced undiscovered potential of these adsorbents.