Enhancing dye adsorption performance of sporopollenin through Thymssol-Menthol-based deep eutectic Solvent functionalization

Dye pollution from industrial wastewater, including that from the batik industry, threatens aquatic ecosystems and water resources. Adsorption is a cost-effective and sustainable method for dye remediation. This study focused on synthesizing thymol-menthol-based deep eutectic solvent functionalized sporopollenin (T:M@DES-Sp) as a new adsorbent for Rhodamine B (RB) remediation. The synthesized adsorbent material showed O-H and C-H stretching peaks at 3311 cm Deep eutectic solvents (DESs) have emerged as promising alternatives to conventional organic solvents due to their low cost, low toxicity, and biocompatibility. Owing to their unique physicochemical properties, DESs have been widely applied in environmental applications, particularly as effective organic coating agents for adsorbents to enhance adsorption performance. Although numerous studies have reported the use of deep eutectic solvents (DESs) to modify materials such as activated carbon and biomass-based adsorbents, the functionalization of sporopollenin (Sp) with DESs remains unexplored. In this study, thymol–menthol deep eutectic solvents (T:M@DES-Sp) were employed for the first time to functionalize the surface of Sp, producing the hybrid material T:M@DES-Sp. Despite its promising potential, the adsorption performance, recyclability, selectivity, and interference behavior of T:M@DES-Sp in real wastewater matrices have not been comprehensively investigated. Therefore, this study systematically evaluates these aspects, providing the first comprehensive assessment of T:M@DES-Sp for dye removal and offering new insights into its practical application as a sustainable adsorbent for wastewater treatment.