Acid-base Tunable Deep Eutectic Solvent Based On 2-methylimidazole And P-toluenesulfonic Acid For The Preparation Of Metal-Organic Frameworks And Their Catalytic Performance

During the preparation of nanomaterials by liquid-phase precipitation,the characteristics of the solvent have obvious influence on the properties of the synthetic material.The organic or inorganic solvents used in the traditional liquid-phase precipitation method are environmentally unfriendly.During the preparation process,additives are needed to adjust the pH value of the solution,which would corrod the equipment and increases the complexity of the system.In this paper,a green deep eutectic solvent based on 2-methylimidazole and p-toluenesulfonic acid is used to replace the traditional solvent for the preparation of nanomaterials.The pH of the solvents can be controlled without adding other reagents,only by adjusting the ratio of hydrogen bond donor(HBD)and hydrogen bond acceptor(HBA).In addition,p-toluenesulfonic acid is also easy to coordinate with metal ions,which plays a regulatory role in the synthesis of metal-organic framework.The main research focuses of the paper are as follows:The calculation of ?-profile has determined that there is a strong hydrogen bond between 2-methylimidazole and p-toluenesulfonic acid,which can form the deep eutectic solvent.Here,a series of acid-base adjustable eutectic solvents were synthesized and their compositions were analyzed.By using the acid-base tunable deep eutectic solvent,the metal-organic framework UiO-66 was prepared by precipitation.The synthesis rate of UiO-66 is significantly accelerated,the material yield reaches 87.5%in 2 h at 50? and normal pressure.The synthesized UiO-66 has good catalytic effect on the acetalization of several aldehydes with methanol.In this paper,through a series of characterization,the mechanism of accelerating the synthesis of UiO-66 was also explored.MIL-101(Fe)and BiVO4/Bi2WO6 materials were synthesized by same method with deep eutectic solvent.There is no need to add other regulators when synthesizing MIL-101(Fe).The synthesized BiVO4/Bi2WO6 materials exhibited better adsorption performance and photocatalytic activity than those synthesized under normal conditions.The above indicates that the acid-base tunable deep eutectic solvent and synthesis method can be used for the synthesis of metal organic frameworks and and optimization of other catalysts.