Selective adsorption of antimony(III) from aqueous solution by ion-imprinted organic–inorganic hybrid sorbent: Kinetics, isotherms and thermodynamics

• We developed a Sb(III)-imprinted silica-supported organic–inorganic hybrid sorbent.
• Surface imprinting technique and sol–gel process was used to prepare the Sb(III)-imprinted sorbent.
• Experimental data followed the Langmuir model and pseudo-second-order kinetic model.
• Adsorption process of Sb(III) on the imprinted sorbent was spontaneous and exothermic.
• Sb(III)-imprinted sorbent can be promising for the selective removal of Sb(III) from aqueous media.

In this work, a novel Sb(III)-imprinted organic–inorganic hybrid sorbent was synthesized by surface imprinting technique combined with a sol–gel process, and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and N2 adsorption–desorption isotherms. The imprinted sorbent showed the higher capacity and higher selectivity than that of non-imprinted sorbent. The optimal pH range for adsorption of Sb(III) was 3.5–6.5. The imprinted sorbent possessed a rapid kinetics for adsorption of Sb(III) with saturation time of 20 min. After nine adsorption/desorption cycles, no obvious decrease of adsorption capacity was observed. The experimental data showed that the adsorption process obeyed the pseudo-second-order rate mechanism and Langmuir isotherm. The thermodynamic parameters indicated that the adsorption of Sb(III) on the imprinted sorbent was an exothermic and spontaneous process.