Coagulation mechanism of cellulose/metal nanohybrids through a simple one-step process and their interaction with Cr (VI).

• Coagulation mechanism and binding mode with Cr (VI) are deeply described. • Cellulose/metal nanohybrids were prepared through one-step coagulation. • Combination of natural polymer and metal nanoparticles with a simple technology for Cr (VI) removal. • 3D porous networks of nanohybrids provide multiple adsorption sites for Cr (VI). • Nanohybrids selectively interacted with Cr 2 O 7 2− through Fe O ... Cr interactions. In this work, the coagulation mechanism of the cellulose/metal nanohybrids and the binding mode with Cr (VI) are deeply described. Nanohybrids with 3D porous networks were prepared from cellulose/Fe 2 O 3 -SO 3 H solutions through a simple one-step coagulation process in NaCl aqueous solutions. The structure and properties of nanohybrids were characterized by SEM, EDS, XRD, FTIR, and XPS. The cellulose/metal nanohybrids have a langmuir maximum adsorption capacity of 11.46 mg/g. The dissolved metal nanoparticles could form strong hydrogen bonding with cellulose by breaking the intermolecular hydrogen bonds between the polymer molecules. The porous networks of cellulose/metal nanohybrids provided multiple adsorption sites for Cr 2 O 7 2− anion through Fe O ... Cr interactions. The cooperation between cellulose and Fe 2 O 3 -SO 3 H nanoparticles makes the hybrids exhibiting a satisfactory selectivity and affinity for Cr (VI). The cellulose/metal nanohybrids selectively interacted with Cr 2 O 7 2− via Fe atom from Fe 2 O 3 and oxygen atom from SO 3 − groups. The Cr (VI) adsorption occurred via a two-step process, the first of them was the initial adsorption of Cr 2 O 7 2− on cellulose/metal nanohybrids surface, followed by the rearrangement of Cr 2 O 7 2− molecules and the consecutive growth of Cr 2 O 7 2− aggregate layers. [ABSTRACT FROM AUTHOR]