N-aminoguanidine modified persimmon tannin: A new sustainable material for selective adsorption, preconcentration and recovery of precious metals from acidic chloride solution

► Preparation of new adsorption material by the introduction of N-aminoguanidine ligands on the surface of persimmon tannin. ► High selectivity of the material towards Au(III), Pd(II) and Pt(IV) over base metals from acidic chloride media. ► Reduction of adsorbed Au(III) to elemental gold and very high loading capacity of the material. ► Highly efficient sorption material having high selectivity and adsorption efficiency than that of commercial adsorbents.