Efficient adsorption of fluorescein sodium by diatomite-loaded Co-doped MIL-125Ti

The removal of environmental pollutants by green and efficient means has always been a hot issue in research. However, adsorption has been proved to be an important means to remove organic pollutants in water. In this work, a diatomite-loaded Co-doped MIL-125Ti composite adsorbent was synthesized by a simple and mild solvothermal method. The structure and morphology of the materials were characterized by SEM, FT-IR and XRD. The results show that the obtained Co@MIL-125Ti@DE has better void structure and thermal stability than MIL-125Ti. The maximum adsorption capacity of Co@MIL-125Ti@DE for fluorescein sodium is as high as 622.84 mg/g, which is better than MIL-125Ti (401.55 mg/g). The adsorption process conforms to Langmuir isotherm and pseudo-second-order kinetic model. In summary, this study provides a new idea for the construction of bimetallic MOFs materials to efficiently remove organic pollutants in water.