Photocatalysis activation of peroxodisulfate over the supported Fe3O4 catalyst derived from MIL-88A(Fe) for efficient tetracycline hydrochloride degradation

Within this paper, the MIL-88A(Fe) particles were immobilized onto the commercial porous block substrate (PBS) to form MIL-88A/PBS via a simple room-temperature synthesis method, which was further calcined at high temperature like 400 °C, 500 °C, 600 °C and 700 °C to obtain Fe3O4@PBS (M−Fe3O4−T@PBS). Upon the irradiation of white light, the peroxodisulfate (PDS) was activated over the as-obtained M−Fe3O4−T@PBS to accomplish tetracycline hydrochloride (TC) degradation in the simulated wastewater. The results revealed that 97.5% and 92.8% TC with the initial concentration of 10 mg L-1 could be degraded within 40.0 min via PDS activation over the optimum catalyst M−Fe3O4−600@PBS under white light and real sunlight irradiation, respectively. The influence factors including PDS dosage, pH values and co-existing ions toward the degradation performance of M−Fe3O4−600@PBS were investigated. Importantly, M−Fe3O4−600@PBS could accomplish extremely simple recyclability and excellent reusability, affording high oxidative degradation even after 30 successive recycles. The possible degradation mechanism explored via different methods like active species capture experiments, electron spin resonance (ESR) determination as well as the corresponding electrochemical analyses. Furthermore, the possible pathways of TC degradation were depicted based on Liquid Chromatography-Mass spectrometry (LC-MS) technology, in which the toxicity of the intermediates decreased based on the quantitative structure–activity relationship (QSAR) evaluation. This work revealed that the immobilized Fe-based MOFs derivatives catalysts possessed great potential in real and large-scale wastewater remediation.