Combinative effects of L-asparagine ligation and pH modifications in tuning the surface and pore environment of biocompatible amorphous zirconium coordination polymers

Amorphous coordination polymers (CPs) are one of the important classes of porous materials, that are gaining attention and providing us with an exciting opportunity to synthesize novel functional materials. Amorphous CPs have practical applications in the domain of material science for a wide range of applications, including biomedical, supercapacitors, gas storage, drug delivery, pollution control, and many others. Though several metal ions and ligands are available, the synthesis of CP with a biocompatible metal ion zirconium and a bidentate ligand, an amino acid (L-Asparagine) offers an eco-friendly CP with high surface area for a variety of applications. Herein, we report the synthesis of amorphous Zr-CPs_Asn using three different pH conditions using modifiers namely, acid, base, and neutral which are thermally stable up to 250 °C. The role of pH modifiers in tuning the surface and pore environment is studied in detail using the BET, FESEM, and EDX analyses and the results are compared. It is interesting to the role of an acidic modifier, which tunes the surface area, and the basicity improves the pore environment, comparatively. Amorphous CPs and innovative synthesis have received attention in recent studies because of their potential and possible applications in a variety of material sciences fields, specifically, heavy metal ion adsorption in water remediation.