Preparation Of TiO₂@GO@C Nanofiber Membrane And Study Of Its Photocatalytic And Mechanical Properties

With the acceleration of industrialization worldwide,the impact of organic pollutants on water pollution can not be ignored.TiO₂ has great prospects for photocatalytic degradation of pollutants due to its excellent photocatalytic performance,low cost,non-toxicity,and chemical stability.However,it has a wide band gap,high photoelectron-hole recombination rate and difficult recovery,which limites the development of TiO₂ in the industry.In response to these questions,the research contents of this topic are as follows:（1）Titanium isopropoxide is used as precursor（Ti-source）,glacial acetic acid is a hydrolysis inhibitor,N,N-dimethylformamide（DMF）is used as a solvent,and polyacrylonitrile（PAN）is a polymer.The electrospinning method was used,and then the nanofibers were pre-oxidized in a muffle furnace and carbonized in a tube furnace to prepare four nanofiber membranes of C,TiO₂@C,GO@C and TiO₂@GO@C.The microstructure and morphology of the above four nanofiber membranes were characterized by XRD,SEM and TEM.The results show that the C,TiO₂@C and TiO₂@GO@C nanofiber membranes exhibit a three-dimensional porous structure;The TiO₂ nanoparticles are coated on a C nanofiber membrane or a GO nanosheet.（2）The bonding relationship of TiO₂@GO@C materials was analyzed by XPS and Raman detection methods.It was found that GO could bond with titanium dioxide preferentially and form a pea-like structure of TiO₂@GO due to its abundant surface functional groups such as C=O and C-OR.The pea-like structure of TiO₂@GO could be wrapped in the C nanofibers film,thus forming a peapod-like structure of TiO₂@GO@C.（3）According to the degradation effect of nanofiber membrane on methylene blue,the photocatalytic performance is determined,the mechanical properties of nanofiber membrane were tested by electronic single-fiber strength machine.The photocatalytic mechanism and the mechanism of mechanical properties change of GO modified nanofibers were discussed and studied.The results show that the peapod-like structure of TiO₂@GO@C has excellent photocatalytic and mechanical properties.In terms of photocatalysis,the pea-like structure can avoid the aggregation of titanium dioxide,enhance their crystallinity and prevent the transformation of anatase phase titanium dioxide;the pea-like structure can also reduce the recombination of hole-electron pairs,increase the distance of hole transport,and improve the photocatalytic degradation performance on the basis of porous structure of C;In terms of mechanical properties,in the process of force transmission,the TiO₂@GO pea-like structure in the TiO₂@GO@C nanofiber membrane can play a good role in dispersion strengthening,so that the mechanical properties of the nanofiber membrane are greatly improved.（4）The effects of the amount of titanium dioxide on the microstructures,morphologies,photocatalytic and mechanical properties of the nanofibers were discussed,and the effects of the amount of GO on the photocatalytic and mechanical properties of the nanofibers were discussed in order to optimize the treatment of the nanofibers.The results showed that the relationship between the amount of GO and titanium dioxide and the properties of TiO₂@GO@C showed a trend of first increasing and then decreasing.Under the system of 1-times of Ti-source,the degradation rate of methylene blue by TiO₂@0.3GO@C nanofiber membrane reached 98.42%,the breaking strength was 356.07 cN/dtex,and the comprehensive performance reached the best.