Enhanced degradation of 2,4-dichlorophenol in groundwater by defective iron-based metal-organic frameworks: Role of SO 3 - and electron transfer

The purposeful formation of crystal defects was regarded as an attractive strategy to enhance the catalytic activity of Fe-MOFs. In this study, the pyrolytic hydrochloric acid-modulated MIL-101-NH (P HMN-2) was fabricated for the first time, and the important role of pyrolysis in the formation of crystal defects was confirmed. PDS was introduced as an enhancer for the P HMN-2/Na SO system. Without pH adjustment, 99.7 % of 2,4-DCP was removed by the P HMN-2/Na SO /PDS system in 180 min. The catalytic performance of P HMN-2 improved 2.5-fold than that of MIL-101-NH . It was found that the high density of Fe-CUSs on P HMN-2 were the major active sites, which could efficiently react with SO to generate ROS through electron transfer. The results of quenching experiments, probe tests, and EPR tests indicated that SO , SO , O , OH, and SO were involved in the 2,4-DCP degradation process, with SO , SO , and O playing major roles. Moreover, P HMN-2 could effectively degrade 2,4-DCP for 148 h in a fixed-bed reactor with excellent stability and reusability, indicating a promising catalyst for practical applications.