Plant tannin immobilized FeO@SiO microspheres: A novel and green magnetic bio-sorbent with superior adsorption capacities for gold and palladium.

In this paper, a new core-shell nanostructured magnetic bio-based composite was prepared by immobilizing persimmon tannin (PT) onto FeO@SiO microspheres, and the as designed FeO@SiO@PT was utilized for adsorptive recovery of Au(III) and Pd(II). The preparation, morphology, composition and magnetic property of FeO@SiO@PT were characterized. Adsorption parameters of FeO@SiO@PT towards Au(III) and Pd(II) including initial pH, reaction time, initial concentration of metal ions, effect of acidity and interference of coexisting metal ions were investigated.