High-Efficiency Photodynamic Antibacterial Activity of NH₂-MIL-101(Fe)@MoS₂/ZnO Ternary Composites

Abstract

Bacterial infections are a serious threat to human health, and the development of effective antibacterial agents represents a critical solution. In this study, NH2-MIL-101­(Fe)@MoS2/ZnO ternary nanocomposites are successfully prepared by a facile wet-chemistry procedure, where MoS2 nanosheets are grown onto the MIL-101 scaffold forming a flower-like morphology with ZnO nanoparticles deposited onto the surface. The ternary composites exhibit a remarkable sterilization performance under visible light irradiation toward both Gram-negative and Gram-positive bacteria, eliminating 98.6% of Escherichia coli and 90% of Staphylococcus aureus after exposure to visible light for 30 min, a performance markedly better than that with NH2-MIL-101­(Fe)@MoS2 binary composites and even more so than MoS2 nanosheets alone. This is ascribed to the unique electronic band structure of the composites, where the separation of the photogenerated carriers is likely facilitated by the S-scheme mechanism in the NH2-MIL-101­(Fe)@MoS2 binary composites and further enhanced by the formation of a p–n heterojunction between MoS2 and ZnO in the ternary composites. This interfacial charge transfer boosts the effective production of superoxide radicals by the reduction of oxygen, and the disproportionation reaction with water leads to the formation of hydroxy radicals, as attested in spectroscopic and microscopic measurements. Results from this study highlight the significance of structural engineering of nanocomposites in the manipulation of the electronic band structure and hence the photodynamic activity.

Novel double-layer core–shell photocatalyst CdS–TiO2@NH2-MIL-101: enhanced conversion of CO2 and CH4 at ambient temperature

“…1a. It could be found that NH 2 -MIL-101 exhibited characteristic peaks at 8.9°, 10.3°, 16.4°, 20.2°, and 24.5°, which were consistent with the data reported in the literature, 29,34,35 indicating that the pure phase NH 2 -MIL-101 material was successfully prepared. Furthermore, the characteristic peaks of TiO 2 at 25.34° and 48.04° could also be observed.…”

Unveiling the antibacterial strategies and mechanisms of MoS2: a comprehensive analysis and future directions

“…116 The Z-scheme heterojunction, on the other hand, offers a more efficient charge separation and transfer mechanism, but requires a more complex and precise design. 115 In our previous research, a ternary composite photocatalyst material NH 2 -MIL-101(Fe)@MoS 2 /ZnO has been designed with both a step-scheme heterojunction and P-N junction, which exhibits high-efficiency photodynamic antibacterial activity, 144 as illustrated in Fig. 9.…”

Current status and prospects of MIL-based MOF materials for biomedicine applications

“…4, which exhibited significant bactericidal performance against both Gram-negative and Gram-positive bacteria under visible light irradiation, with a killing rate of 98.6% for E. coli and 90% for S. aureus after 30 minutes of visible light irradiation. 42 The antibacterial properties of Fe-MOFs make them promising candidates for antibacterial therapy. With further research into the properties and applications of these materials, it is expected that Fe-MOFs will have more opportunities for use in antibacterial therapy.…”

“…4, which exhibited significant bactericidal performance against both Gram-negative and Gram-positive bacteria under visible light irradiation, with a killing rate of 98.6% for E. coli and 90% for S. aureus after 30 minutes of visible light irradiation. 42…”