Abstract
This study presents the development of a hybrid nano-adsorbent utilizing zirconium dioxide (ZrO2) nanoparticles to enhance metal extraction efficiency. Through a meticulous twostep surface modification process, the goal was to improve interfacial properties and increase metal-binding capacity. The initial step involved the optimization of synthesis conditions and immobilization of Poly(ethylene glycol), α,ω-bis phosphonic acid (PEG2P) on the ZrO2 nanoparticles. Various molar ratios were examined, and 1000:1 was identified as optimal. The second step utilized carbamoyl phosphonic acid ligand (L: DBCPPA) via a Brönsted acid-base reaction, yielding ZrO2-PEG2P-L nanomaterials with a yield of approximately 97%. Comprehensive characterizations confirmed the success of each step, including thermogravimetric analysis (TGA), attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and nuclear magnetic resonance (31P-NMR) analysis. The modified adsorbents were tested for Au(III) adsorption, showing enhanced efficiency and selectivity. Additionally, their robustness was validated through multiple adsorption-stripping cycles, demonstrating stability and reusability without contamination. This research highlights the importance of ligand design, reaction condition optimization, and composite ligand systems in enhancing metal extraction capabilities. The findings contribute to advanced methodologies for metal extraction, aiming for improved purity, efficiency and sustainability of materials science and environmental remediation.