Preparation and application of a targeted magnetically separated catalyst for sulfonamides degradation based on molecular dynamics selection and mechanism analysis

As refractory pollutants, sulfonamides (SAs) are widely distributed in the aquatic environment. The existing methods for advanced oxidation used to remove SAs from water received wide attention. In this study, surface molecular imprinting technology has been used to prepare targeted catalysts that can be rapidly separated. The results showed that molecularly imprinted catalysts can significantly improve the removal capacity of sulfonamides. When compared to Fe3O4, the removal rates observed for 3 different SAs increased by 98, 20 and 61%, respectively over 480 min on target catalyst and a good magnetic separation effect was observed in short time. The theoretical results show that the optimal imprinted conditions can be quickly determined by analyzing the energy variation in the optimized system. Combined with energy analysis and free radical detection, the effects of weak interactions such as hydrogen bonds and van der Waals forces on the selective recognition ability of the materials were determined. The results also show that the selective recognition process mainly exists in the higher activity groups (-NH2 and -NH-) that connect to the benzene ring in SAs. The catalysts also maintain their targeted catalytic activity in complex water samples. The results show that computational chemistry and molecular imprinting can be used to design and prepare a targeted catalyst quickly and analyze the mechanism of its targeted degradation process. This study can provide reference for the rapid design of targeted catalysts and an improvement in the degradation efficiency of refractory pollutants found in wastewater.