Shungite/poly(vinyl alcohol) hybrid hydrogels: An efficient adsorption material for rare earth metals in aqueous media

Abstract

AbstractRare earth elements play a pivotal role in modern technologies, thereby driving an escalating demand for their procurement. To effectively extract these elements from aqueous solutions, it is imperative to explore innovative sorbent materials. In this context, a hydrogel sorbent material was developed by employing poly(vinyl alcohol) (PVA) and shungite—an economical, naturally occurring, easily processable, and sustainable material. This was achieved through the freezing–thawing method, employing sodium borate as a crosslinking agent. The physicochemical characteristics of the hydrogels were determined through scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier‐transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, Zetasizer analysis, and elemental analysis. The shungite‐incorporated PVA hydrogels displayed notable characteristics, including a substantial swelling capacity of 61% and a specific surface area of 32.8 m2/g. Most significantly, these hydrogels exhibited a remarkable affinity for La3+ ions, with an uptake ratio of 134 mg/g. This was followed by Nd3+, Dy3+, and Er3+ ions, which displayed uptake ratios of 79, 74, and 73 mg/g, respectively.