Three-dimensional nanoporous starch-based material for fast and highly efficient removal of heavy metal ions from wastewater

The development of advanced adsorbents with fast adsorption rate, simple preparation, low cost, and high adsorption capacity is one of the most important topics for water purification. Herein, a novel and pollution-free adsorbent, three-dimensional nanoporous starch-based nanomaterial (3D-PSN), was prepared via sacrifice template method and functionalized for the first time in this work. Relevant characterization was performed through XRD, SEM, TGA, zeta potential analysis, FTIR, and XPS to confirm the formation of nanomaterials. Owing to its unique three-dimensional network nanostructure and abundant active sites, this adsorbent displayed outstanding adsorption properties for heavy metal ions removal, as high as 532.28 mg/g for Cd (II), 381.47 mg/g for Hg(II), 354.15 mg/g for Cu(II), 238.39 mg/g for Pb(II), completed within 30 min. In this process, the pseudo-second-order kinetic model appeared more consistent with the adsorption kinetic data, and the adsorption behavior complied with the Langmuir adsorption model. The adsorption mechanism mainly replied on the ion-exchange reaction, as well as chemical complexation formation. This adsorbent has remarkable recyclability, exhibiting strong application prospects for water purification and environmental remediation.