Abstract: Molecular imprinting has been conducted on the surface of TiO2 particles to enable the recognition of dibenzothiophene (DBT) molecules. This was achieved via the use of a novel surface molecular-imprinting technique. The adsorption behaviour of the dibenzothiophene-imprinted material (D-MIP/TiO2) was evaluated using batch adsorption experiments to determine the kinetic, isotherm and thermodynamic parameters. The experimental results showed that the adsorption process followed pseudo-second-order kinetics and that the experimental data were well fitted by the Freundlich adsorption equation. This indicated that adsorption involved a multilayer process. Values of the Gibbs' free energy (Δ G0) ranged from -7.11 kJ/mol to -9.36 kJ/mol over the temperature interval 298-318 K, indicating that the adsorption was endothermic in nature. In addition, D-MIP exhibited selective recognition of DBT relative to other similar compounds such as benzothiophene (BT), 4-methyldibenzothiphene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). In the corresponding selectivity test, D-MIP/TiO2 showed a greater adsorption capacity towards DBT than BT, 4-MDBT and 4,6-DMDBT. The large imprinting factor (ca. 2.5) exhibited by D-MIP/TiO2 for DBT could be explained in terms of a covalent assembly mechanism
Template and target information: dibenzothiophene, DBT