A Safe And Versatile Un-expensive Surface Fluorination Modification Technology And Its Application

The small particle size of micro-nano-particulate materials,with the vast majority of atoms located at the surface of the particles,often have special surface properties that provide opportunities for surface modification.Fluorine has the smallest atomic radius and a high electron-absorbing capacity,imparting a variety of unusual properties to fluorine-doped compounds.In this paper,a variety of fluorine-doped compounds,including inorganic carbon materials,metal oxides,bimetallic oxides,sulfides,nitrides,carbides and organic polymers,were synthesized through a gas-solid phase reaction using 1,4-diiodoperfluorobutane（1,4-C₄F₈I₂）as the fluorination reagent and were characterized in a series of reactions in a closed vessel,and two of the fluorine-doped compounds were selected for performance studies.（1）A large number of compounds were prepared by fluorine doping and three of them,including graphene,MoS₂ and TiO₂,were selected for specific surface analysis and characterized by SEM,TEM,XPS and XRD to show that fluorine atoms are uniformly doped in the structure of the compounds and that for metal oxides fluorine readily replaces lattice oxygen to form fluorine-metal bonds,affecting their corresponding properties.Other compounds were subjected to corresponding XPS tests and most of them could be successfully fluorine doped.The fluorine doping of MoS₂ and graphene using different fluorination reagents further demonstrates the versatility and excellent fluorine doping properties of the fluorination reagent 1,4-diiodoperfluorobutane.（2）PMMA microspheres with a particle size of about 270-880 nm were successfully prepared by soap-free emulsion polymerization,and three-dimensional macropores ordered metal oxides（3DOM Co₃O₄）were prepared by the template method and fluoridated by the same fluorination method.The synthesized compounds were subjected to SEM,TEM,XPS and XRD morphological and structural characterization as well as LSV and EIS electrocatalytic oxygen precipitation（OER）performance tests,and the optimum performance was investigated by controlling the reaction temperature,reaction time and the ratio of fluorinated reagents.The overpotential of the catalyst at a current density of 10 m A cm^-2 was only 380 m V and the catalytic stability was maintained for 30 hours.（3）Three common covalent organic framework materials（COFs）,Schiff base COFs-COF-TpBD and borate esters COFs-COF-5 and COF-10,were synthesized by the solvothermal method,and the three COFs were modified by surface fluorination by the same fluorination means.They all were characterized by a series of structural and morphological,chemical composition and crystal structure.The three F-COFs were successfully loaded onto stainless steel nets（SSNs）by the repeated growth method,and the contact angle test revealed that all three fluorine-doped COFs showed superhydrophobic properties,and the oil-water separation test showed that the fluorine-doped COF-TpBD had good hydrophobic and lipophilic properties,while the fluorine-doped borate COFs showed selectivity towards organic molecules of different diameters due to the reduced molecular pores.