Study On Electrochemical Synthesis Of Zr-MOFs And Its Performance In Detecting Hydroquinone

Metal organic framework materials（MOFs）are widely used in the fields of adsorption and separation,drug sustained release,catalysis and electrochemical sensing due to their large specific surface area,diverse structures and easy adjustment of pore size.There are various synthesis methods of MOFs materials,such as:water/solvothermal method,stirring method,ultrasonic method,diffusion method,etc.The above methods have some disadvantages such as time and energy consumption,harsh reaction conditions and complicated reaction processes,which are not conducive to the industrial production of MOFs.The electrochemical method overcomes the shortcomings of the above synthesis methods,which can quickly synthesize the desired product at room temperature and avoids the impact of external metal salts on the purity of the material.However,there have been few reports on the types of MOFs synthesized by electrochemical methods,so it is still a great chal enge to expand the types of MOFs synthesized by electrochemical methods.In this paper,zirconium-based metal-organic framework materials MOF-801 and UiO-67 were successful y synthesized by electrochemical methods by adjusting the applied voltage,the amount of acetic acid and the reaction temperature for the first time.X-ray diffraction,electron scanning microscopy,Fourier transform infrared spectroscopy and N₂ adsorption and desorption tests were used to characterize the structure,morphology and performance of synthetic materials.The results shown that the MOF-801 material has a high crystal inity and uniform octahedral structure when the dosage of acetic acid is 5～9 m L,the applied voltage is 4～6 V and the reaction temperature is room temperature;When the dosage of acetic acid is 5～7 m L,the applied voltage is 6～8 V and the reaction temperature is room temperature,the obtained UiO-67 material has high crystal inity and uniform tetrahedron structure.The specific surface area of MOF-801 is 720.71 m²/g and the pore size is 0.87 nm;The specific surface area of UiO-67 is 2010 m²/g and the pore size is 1.25 nm.The synthesized MOF-801 and UiO-67 were made into MOF-801-CPE and UiO-67-CPE for electrochemical detection of hydroquinone（HQ）in water.The AC impedance test（EIS）was used to investigate the charge transfer rate.The cyclic voltammetry test（CV）was used to study the effects of different scan rates and buffer solution p H on the peak current of HQ.The stability,anti-interference and reusability of the electrodes were tested.The linear range and detection limit of the electrode material were determined by differential pulse voltammetry（DPV）.The results shown that both MOF-801-CPE and UiO-67-CPE have good stability,anti-interference and can be reused.The linear range of the MOF-801-CPE electrode is 50-1000μmol/L and the detection limit is 5.7×10^-7 mol/L,while the linear range of UiO-67-CPE for detecting HQ is 5-300μmol/L,and the detection limit reaches 3.6×10^-9 mol/L,far below the detection limit of MOF-801-CPE.This may be due to the large specific surface area of UiO-67 compared with MOF-801 material,which can adsorb more HQ to the electrode surface.In addition,the benzene ring in the UiO-67 structure and the benzene ring in the HQ structure became aπ-πconjugated system.This promotes electron transfer between UiO-67 and the organic linker of HQ.