Ti3C2-assisted construction of Z-scheme MIL-88A(Fe)/Ti3C2/RF heterojunction: Multifunctional photocatalysis-in-situ-self-Fenton catalyst

Abstract

The applicability of the conventional Fenton reaction is limited due to several factors, including the high cost and slow redox cycle of Fe3+/Fe2+, the requirement for harsh acidic conditions, and the insufficient presence of hydroxyl radicals for the ring-opening reaction. The combination of photocatalysis and Fenton technology to create a photocatalysis-in-situ-self-Fenton (PISF) system is a viable approach for addressing the inherent limitations of conventional Fenton reactions. Herein, a multifunctional PISF system, MIL-88A(Fe)/Ti3C2 MXene/resorcinol-formaldehyde (MIL-88A(Fe)/Ti3C2/RF, MTR) Z-scheme heterojunction, was designed and constructed for degradating organics and inactivating bacteria. With the assistance of Ti3C2, the degradation rate of TC by MTR catalyst was 4.8 times that of MIL-88A(Fe)/RF catalyst under visible light irradiation. Meanwhile, good degradation performance was maintained after 5 cycling tests. The remarkable TC removal efficiency (97.4 %) and durability were attributed to the synergistic effect of the photocatalytic reaction and Fenton reaction. The photoinduced holes (h+) assist hydroxyl radicals (•OH) generated by the Fenton reaction for deeply mineralizing TC. The degradation intermediates, potential degradation pathways, and intermediates toxicity were comprehensively investigated to gain a deeper understanding of the catalytic process. Moreover, under visible light irradiation, the MTR killed 97.8 % of E. coli and 94.9 % of S. aureus within 120 min, demonstrating good antibacterial activity. This work provides a novel strategy to design PISF catalysts for environmental remediation.