Influence of microwave-assisted synthesis on the structural and textural properties of mesoporous MIL-101(Fe) and NH2-MIL-101(Fe) for enhanced tetracycline adsorption

In this paper, the effect of conventional solvothermal and a microwave-assisted method for the synthesis of MIL-101(Fe) and NH2-MIL-101(Fe) as adsorbents for the removal of tetracycline in wastewater is reported for the first time. The results had shown that the microwave treatment led to a significant reduction in the material synthesis time, which greatly saved the energy. It was also found that the microwave-assisted synthesized material exhibited small particle size, high specific surface area and better adsorption capacity. The introduction of amino group further enhanced the adsorption capacity of MIL-101(Fe). The adsorption capacity of MIL-101(Fe) and NH2-MIL-101(Fe) samples for tetracycline adsorption by microwave assisted synthesis method reached up to 332 mg/g and 378 mg/g, respectively. Moreover, the adsorption isotherm was well-fit with Freundlich model, indicating a multilayer adsorption. The kinetic studies indicated that the reaction followed pseudo second-order reaction kinetics with a best fit to the theoretical value. Due to the higher adsorption efficiency and lower energy consumption of the synthesis, the as-prepared microwave assisted materials could be used as potential adsorbents for different pollutants in wastewater.