Efficient lithium-ion recovery using selective organically crosslinked HTO-polyacrylamide-graphene nanocomposite hydrogels

Summary

Efficient extraction of Li⁺ ions from seawater is critical for sustainable energy storage technologies. This study integrates H₂TiO₃ (HTO) into a thermo-mechanically reinforced, organically crosslinked polyacrylamide-commercial graphene (PAM-CG) nanocomposite hydrogel to enhance Li⁺ adsorption and material recovery. Fourier transform infrared spectroscopy (FTIR spectroscopy) and X-ray diffraction analyses confirmed the incorporation of HTO, while thermal analysis showed improved stability (192.5°C vs. 188.2°C for PAM). The porous, wedge-shaped morphology observed by SEM and BET analysis facilitated effective ion capture. The HTO-PAM-CG hydrogel exhibited an adsorption capacity of 42.5 mg g⁻¹, followed by pseudo-second-order kinetics (k = 2.59 × 10⁻³ g mg⁻¹ min⁻¹), and retained high efficiency over nine cycles. These findings highlight the potential of mechanically reinforced polymer-inorganic composites for the selective and recyclable recovery of Li from seawater.