Microwave-assisted solvothermal synthesis of bimetallic metal-organic framework for efficient photodegradation of organic dyes

• Published in: Materials chemistry and physics 2021-11, Vol.272, p.125040, Article 125040
• Main Authors: Nguyen, Hong-Tham T., Tran, Kim-Ngan T., Van Tan, Lam, Tran, Vy Anh, Doan, Van-Dat, Lee, Taeyoon, Nguyen, Trinh Duy
• Format: Article
• Language: English
• Subjects: Bimetallic; Bimetals; Catalysts; Chemical properties; Decomposition; Dyes; Free radicals; Iron; Irradiation; Kinetic; Leaching; Mechanism; Metal-organic frameworks; Methylene blue; MIL−88B(Fe); Morphology; Nickel; Photocatalysis; Photocatalytic performance; Photodegradation; Reliability analysis; RhB dye; Rhodamine; Scavenging; Stability analysis; Synthesis; X ray photoelectron spectroscopy
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2021.125040

Iron metal-framework MIL−88B(Fe) (chemical formula: Fe3O [C6H4(CO2)2]3OH.nH2O) has received much attention as a promising catalyst for the degradation of organic dyes. Unfortunately, some MOFs suffer from a deficiency of stability; thus, limiting their range of applications. To handle this problem, we attempted to replace Fe3+ ions with other metal ions at different ratios to improve the photocatalytic performance. Briefly, M/Fe−MOFs (M = Ni, Mg and Sn) with remarkably different properties were obtained using the microwave-assisted solvothermal method. The morphology of the synthesized bimetallic metal-organic frameworks was characterized by SEM and TEM; while their physical and chemical properties were defined by XRD, FT−IR, Raman, XPS, UV–vis DRS, and BET. The photocatalytic performance of the prepared materials was explored through the photocatalytic degradation of organic dyes (rhodamine B (RhB), crystal violet (CV), methyl orange (MO) and methylene blue (MB)) under irradiation of visible light was explored. The result showed that 10%Ni/Fe-MOF sample achieved above 96 % of RhB removal after 120 min of irradiation. The effects of pH solution, catalyst dosage and RhB concentration on RhB decomposition efficiency were carefully investigated. Furthermore, the present study has proposed a mechanism of RhB dye degradation reaction by bimetallic MOFs catalysts. Additionally, the free radical scavenging experiment has found that OH• and h+ radicals took the main responsibility for RhB decomposition. The stability and reliability of 10%Ni/Fe-MOF were also evaluated via the leaching and reusability tests. Interestingly, the photocatalyst performance experienced a negligible reduction after five consecutive usages. The results are expected to broaden the knowledge of bimetallic MOF synthesis and its applications. [Display omitted] •Bimetallic M/Fe−MOFs (M = Ni, Mg and Sn) were synthesized microwave-assisted solvothermal method•10%Ni/Fe-MOF achieved above 96 % of rhodamine B (RhB) removal after irradiation for 120 min•A mechanism of RhB dye degradation reaction by bimetallic MOFs catalysts has been proposed•The photocatalyst performance experienced negligible reduction after five consecutive usages.