Selective Removal of Thiophene Using Surface Molecularly Imprinted Polymers Based on β-Cyclodextrin Porous Carbon Nanospheres and Polycarboxylic Acid Functional Monomers

For the effective removal of thiophene, a novel surface molecularly imprinted polymer (SMIP/MA@PCNS) was fabricated using porous carbon nanospheres (PCNS-5) as the support matrix and maleic acid (MA) as the functional monomer. Benefiting from the special amphiphilic properties of β-cyclodextrin as the carbon source, PCNS-5 exhibited good dispersion, uniform nanoscale sphere, and high specific surface area, which favored the rapid adsorption rate. Based on the intermolecular hydrogen bonds existing between carboxylic acid functional groups and thiophene, adsorption performances of different unsaturated polycarboxylic acids were investigated systematically. The results revealed that the optimal functional monomer was MA instead of the conventional methacrylic acid. Accordingly, SMIP/MA@PCNS was successfully applied to the direct removal of thiophene in the oil, reaching remarkable sulfur adsorption capacity (22.6 mg S g–1) within 120 min. Moreover, SMIP/MA@PCNS could selectively remove thiophene (16.2 mg S g–1) in the presence of structural analogues (3-methylthiophene, benzene, and cyclopentane) and exhibited an excellent regenerability with nice structural ability. These results indicated that SMIP/MA@PCNS possessed great promise in the desulfurization field.