Synthesis of Mn-Doped Fe-MOFs with Different Ratios and Its Application for Photocatalytic Degradation of Rhodamine B Dye

Abstract

Recent trends in environmental remediation have shifted to the use of metal-organic framework (MOF) composites due to their unique structural properties. It is still challenging to diversify MOFs photocatalysts to fulfill application to treat toxic organic pigments. In this study, Fe-MOF bimetallic materials were synthesized by doping Mn2+ ions at different ratios. The structural and morphological characteristics of the materials were analyzed by XRD, UV-Vis, FT-IR, SEM, and UV-Vis DRS methods. Mn/Fe-MOF bimetallic organic framework materials were used to evaluate the photocatalytic degradation of Rhodamine B (RhB) dyes. The results show that, under the same experimental conditions, the RhB degradation efficiency of Mn/Fe-MOF is enhanced than that of the pristine Fe-MOF catalyst under the influence of visible light. After 120 min, the RhB solution was decomposed to 91.78% by combining 0.1 Mn/Fe-MOF, H2O2, and visible light irradiation. At the same time, the presence of H2O2 in the reaction system also showed a strong impact on the efficiency of RhB degradation. The activity from the two metal centers of Mn/Fe-MOF contributes to the formation of a unique structure and composition that can be used as a photocatalyst for colored wastewater treatment.

Synthesis of Fe–Mn-Based Materials and Their Applications in Advanced Oxidation Processes for Wastewater Decontamination: A Review

“…42,43 For example, Kim et al performed photocatalytic degradation of rhodamine B (RhB) by different ratios of Mn-doped Fe-MOFs (Mn/Fe-MOF bimetallic organic framework materials). 44 The degradation efficiency of Mn/Fe-MOF on RhB after 120 min (91.78%) was higher than that of the pristine Fe-MOF catalyst (85%) due to the synergistic effect of the bimetals. Zhang et al obtained a series of Fe−Mn MOFs (FeMn-MOF-74) with varying crystalline strengths from amorphous to highly crystalline by changing the temperature of the solvothermal (i.e., 100, 120, 135, and 150 °C) (Figure 2b).…”

“…Metal organic frameworks (MOFs) are an emerging type of porous coordination polymers composed of central metals and organic ligands . MOFs and their derivatives have been widely used in catalysis because of their easily adjustable framework, ultrahigh surface area, thermal stability, ordered porous structure, and multiple active sites. , For example, Kim et al performed photocatalytic degradation of rhodamine B (RhB) by different ratios of Mn-doped Fe-MOFs (Mn/Fe-MOF bimetallic organic framework materials) . The degradation efficiency of Mn/Fe-MOF on RhB after 120 min (91.78%) was higher than that of the pristine Fe-MOF catalyst (85%) due to the synergistic effect of the bimetals.…”

Application of Fe-MOFs in Photodegradation and Removal of Air and Water Pollutants: A Review

“…Photoluminescence spectroscopy (PL) and electron cis-resonance (EPR) analyses confirmed the ability of PS to accept photogenerated electrons, thus promoting the degradation of the dye Acid Orange 7 (Figure 2c). Tran et al [67], among others, achieved efficient photocatalytic degradation of RhB using bimetallic Mn/Fe-MOF materials obtained by doping Mn 2+ ions. The activity of these bimetallic centers played a crucial role in shaping unique structures and compositions, ultimately enhancing their photocatalytic ability.…”

Enhanced Heterogeneous Catalytic Activity of Peroxymonosulfate for Rhodamine B Degradation via a CoII-Based Metal–Organic Framework

“…Co 2+ is the most efficient transition-metal ion for PMS activation, but the nonrecyclable nature of Co 2+ during degradation cycles poses significant secondary environmental risks, restricting the widespread usage of homogeneous Co 2+ /PMS systems. − Also, photocatalytic chemical oxidation using potent oxidants can be used to degrade organic pollutants. In fact, transition-metal species in metal–organic frameworks (MOFs) have the same function as substitute catalysts to activate oxidants and produce free radicals. − As catalysts for oxidation processes, only a small number of MOFs have been investigated, − and they are less used as catalysts to activate PMS. The activation of PMS is one of the most important processes to generate sulfate (SO 4 •– ), which has a high standard redox potential (2.5–3.1 V).…”