Thermodynamics, Kinetics, and Mechanism of Luteolin Adsorption on Nickel-Doped Amino-Modified Silica

N -[3-(Trimethoxysilyl)propyl]ethylenediamine, tetraethyl silicate, nickel acetate, and sodium hydroxide solution were reacted through using anhydrous ethanol as the solvent and heated in a water bath to synthesize nickel-doped amino-modified silica adsorbent material (NDAMS). The structure of NDAMS was characterized by utilizing XRD, BET, FTIR, and XPS. The thermodynamics, kinetics and mechanism of luteolin adsorption on NDAMS were examined. The results exhibit that NDAMS achieves a 94.69% adsorption efficiency for luteolin at 298 K, demonstrating excellent adsorption performance. As the temperature increases, the adsorption amount rises, which conforms to the Langmuir model. The adsorption process aligns with the pseudo-second-order kinetic model, with an enthalpy (Δ H ) of 30.68 kJ/mol, entropy (Δ S ) of 198.70 J/(mol K), and Gibbs free energy (Δ G ) of –28.44 kJ/mol at 298 K. NDAMS may adsorb luteolin through a spontaneous, endothermic and monolayer chemisorption process, in which a bond is formed between the doped nickel atoms and the oxygen atoms in the luteolin’s phenolic hydroxyl group.