MgFeTi-LDH/g-C3N4 promote sodium persulfate activation through Fe3+/Fe2+ cycle for efficient tetracycline degradation under visible light irradiation

In this study, various of MgFeTi-LDH/g-C3N4 photocatalytic materials had been successfully synthesized through self-assembly, and the physicochemical and photoelectric properties were thoroughly characterized. Optical performance characterizations of band gaps and VB-XPS spectra revealed that the EVB and ECB alignment of MgFeTi (3:1)-LDH/g-C3N4 composites are consistent with the fundamental characteristics of S-type heterojunctions. MgFeTi (3:1)-LDH/g-C3N4 coupled with sodium persulfate activation for TCH degradation achieved nearly 100% removal efficiency under visible light, surpassing previously reported catalysts. Moreover, five repeated tests of MgFeTi (3:1)-LDH/g-C₃N₄ showed negligible change in the removal rate of TCH, indicating its potential value for industrial applications. Furthermore, the catalytic degradation pathway and mechanism for MgFeTi (3:1)-LDH/g-C3N4 have been elucidated through LC-MS analysis, radical capture, and characterization. In addition, the high efficiency of TCH degradation is attributed to the synergy of Fe3+、Fe2+, SPS, and active species such as •OH, SO4•−, and •O2−. Finally, the QSAR analysis and OD600 values suggest that the degradation pathway and time lead to a reduction in toxicity and the potential risk to the degradation liquid. This study offers simple, economical approach to completely degradation TCH, also providing practical application prospects in wastewater treatment.