Improved charge transfer and enhanced visible light photocatalytic activity of Bi2O3@Fe-MOF for degradation of Rhodamine B and Triclopyr

Objectives: Metal organic frameworks (MOFs) composites, integrated with metal oxides augment the inherent characteristics of the original frameworks. Present study aims to investigate and assess the potential of Bi2O3@Fe-MOF composites in efficient photocatalytic degradation of two distinct organic pollutants, namely Rhodamine B (RhB) dye and Triclopyr (TC) pesticide. Methods: A series of Bi2O3@Fe-MOF was synthesized by changing the Fe: Bi molar ratios and following the solvothermal method. Fabricated materials were analyzed primarily for crystalline arrangements, morphology features and chemical compositions, band gap energies, functional moieties, recombination of charge carriers, and surface charge. These assessments were carried out with the different advanced techniques including XRD, FTIR, FESEM and EDX, UV-Vis DRS, PL, and Zeta potential analysis. The synthesized composites were studied for their ability in photocatalytic breakdown of RhB and TC under visible light irradiation. The pseudo first order kinetic model is implemented to study the degradation kinetics of the pollutants. Trapping experiments were performed to determine the reactive species responsible for the degradation reaction. Results and conclusions: The study showed that the crystalline nature, morphology, and optical absorbance of the prepared composites changed with Fe:Bi molar ratio. The degradation efficiency of Bi2O3@Fe-MOF-3 for RhB and TC was 91.79% and 88.42%, respectively, in 120 min, making it the most effective synthesized material. The pseudo-first-order kinetic model was in good agreement with the experimental data. The trapping experiments revealed that hydroxyl radicals (center dot OH) were the main contributors to the degradation reaction. This study concluded that Bi2O3@Fe-MOF composites are promising photocatalysts for the degradation of organic pollutants. The highest photocatalytic performance of Bi2O3@Fe-MOF-3 is attributed to the connected interfaces between Bi2O3 and Fe-MOF phases, which facilitate effective charge injections and separation.

Automated summary

In this study, a series of Bi2O3@Fe-MOF composites were synthesized and characterized. The results showed that Bi2O3@Fe-MOF-3 exhibited high degradation efficiency for RhB and TC, making it a promising photocatalyst for the degradation of organic pollutants.