Preparation And Properties Of Co₃O₄ Loaded PVDF/PES Fibers

As a transitional metal oxide,Co3O4 has excellent electrochemical properties,thermal stability and photocatalytic properties.In order to explore its potential value in the fields of energy,photocatalysis and oil-water separation,this paper prepared PVDF/PES@Co304 nanofibers by low-temperature heat treatment,electrostatic spinning and hydrothermal synthesis.And Co3O4 nanosheets or nanoparticles were successfully loaded on PVDF/PES fibers.The effective combination of organic and inorganic fields could expand the applications of Co3O4.First of all,orthogonal test method was used to design the test scheme,and the electrostatic spinning method was used to prepare PVDF/PES nanofibers.In order to find out the optimum parameters of fiber preparation,the visual analysis method was implemented to explore the influence of concentration,solvent ratio,speed and voltage on the fiber diameter.In addition,PVDF/PES nanofibers with different solute ratios were prepared.Through the characterization and analysis of SEM,EDS,FTIR,DSC-TGA and mechanical properties,the parameters of the PVDF/PES nanofibers with the best performance were determined as follows:spinning solution concentration of 19%,solute(PVDF:PES)ratio=1:1,solvent(DMF:Acetone)ratio=7:3,spinning speed of 1mL/h,20kV and spinning distance of 17cm.On this basis,PVDF/PES/Co(CH3COO)2 composite nanofibers with different parameters were prepared,and the composite fibers were calcined in muffer furnace at different temperatures or times.According to the characterization and analysis of SEM,EDS,FTIR,XPS,DSC-TGA and mechanical properties,it was found that higher heat treatment temperature or longer heat treatment were beneficial to the oxidation of Co(CH3COO)2.Adding appropriate amount of Co(CH3COO)2 was beneficial to improve the mechanical properties of the fibers and was more suitable for the subsequent water heat treatment.After heat treatment,hydrothermal synthesis of PVDF/PES/Co(CH3COO)2 composite nanofibers was carried out.The effects of different heat treatment temperatures,Co(CH3COO)2 content,growth duration,growth temperatures and growth fluids were investigated on the morphology and properties of Co3O4.Results showed that the water fluid temperature was below 900C or the content of HMTA was high in the liquid,more Co3O4 nanosheets or nanoparticles loaded PVDF/PES fiber could be easily obtained;Howerver,when the temperature of hydrothermal reaction is higher than 90 C or the mass of Co(NO3)2 in the growth liquid is relatively large,only Co3O4 nanoparticles were loaded on PVDF/PES fibrous substrate.In this experiment,Co3O4 nanosheets or nanoparticles existed in two valence states of Co2+and Co3+,and the corresponding crystal type of Co3O4 was cubic spinel.