Preparation Of Nickel-based MOFs Derivatives And Their Adsorption Properties

In recent years,metal-organic frameworks（MOFs）have been widely used in the field of adsorption due to their advantages such as large pore size and specific surface area,low crystal density,and tunable pore size.However,the poor stability and mechanical performance of MOF materials limit their practical application.MOF derivatives not only effectively retain the porous and high specific surface area advantages of MOFs,but also have good stability,showing promising application prospects in the field of adsorption.In this study,a series of nickel-based MOF derivatives were prepared simply and controllably by in-situ sulfidation or calcination using nickel-based MOFs as precursors,and their desulfurization performance was investigated,broadening the application of MOFs materials in the field of adsorption.The main research content of this article is as follows:（1）Using foam nickel as the substrate,Ni Fe-MOFs nanosheets were synthesized in situ on its surface,and then sulfurized at room temperature to prepare porous Ni₃S₂/Fe S₂/NF composite material.The structure and surface properties of Ni₃S₂/Fe S₂/NF composite material were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,thermal gravimetric analysis（TGA）and other methods.The response surface optimization method was used to explore the optimal adsorption desulfurization conditions of Ni₃S₂/Fe S₂/NF composite material for simulated oil,which were 20°C and 111.87 min of adsorption,resulting in a desulfurization rate of 96.71%.Ni₃S₂/Fe S₂/NF showed high repeatability and the adsorption reaction process of thiophene followed the quasi-second-order kinetic equation.The isothermal adsorption curve of Ni₃S₂/Fe S₂/NF was consistent with the Freundlich equation.（2）Using cetyltrimethylammonium bromide（CTAB）as a pore-forming agent,porous Ni-BTC precursor was prepared by solvent-thermal reaction,and then porous Ni（OH）₂ was synthesized through solid-solid conversion in an alkaline solution.The structure and surface properties of porous Ni（OH）₂ were characterized by SEM,XRD,XPS,N₂ adsorption-desorption（BET）,and the response surface optimization method was used to explore its optimal adsorption desulfurization conditions for simulated oil,resulting in a desulfurization rate of 95.9%.The porous Ni（OH）₂ material showed good repeatability and the adsorption reaction process of thiophene followed the quasi-second-order kinetic equation.The isothermal adsorption curve of porous Ni（OH）₂ was consistent with the Langmuir equation,and the adsorption mechanism of Ni（OH）₂ for thiophene was explored using first-principles calculations.（3）A bimetallic MOFs（Ni Fe-MOFs）precursor was prepared by hydrothermal method,and a magnetic Ni Fe₂O₄ material was prepared by high-temperature calcination.The structure and surface properties of Ni Fe₂O₄ were characterized by SEM,TEM,XRD,XPS,BET,TGA,and VSM,and the optimal adsorption and desulfurization conditions for simulated oil were explored using response surface optimization method,achieving a desulfurization rate of 88.13%.The Ni Fe₂O₄ magnetic material exhibited good repeatability and its adsorption process for thiophene followed a pseudo-second-order kinetic equation,while its isotherm adsorption curve followed the Freundlich equation.The adsorption mechanism of thiophene on Ni Fe₂O₄ was also explored using first-principles calculations.