Graphitic Carbon Nitride Loaded On Polyethylene Tere-Phthalate Nanofibers For Degrading Antibiotics Under Solar Irradiation

The large application of antibiotics to prevent diseases in humans and livestock has led to the presence of sublethal antibiotics content in the environment.This situation increases the threat of developing a stronger resistance to antibiotics in every region of the world.The sublethal antibiotics content in the environment brings added urgency to the need to degrade antibiotics to prevent the growth of antibiotic resistance and the consequent public health crisis.Currently,photocatalysis has attracted wide notice for degrading pollutants over inexhaustible sunlight.What's more,graphitic carbon nitride?g-C₃N₄?is widely applied in photo-synthesis,energy conversion and water purification on account of its high stability,visible light response,multiple preparation methods and the structure that is easy to tailor.Its practical implementation is,however,still restricted because of the difficulty of recycling g-C₃N₄ used in powder or nanoscale photocatalysts.Thus,aimed to improve its performance,dispersity,reusability and stability,nanofibers was applied to load the g-C₃N₄,which can be used to degrade the antibiotics.Herein,we highlight a facile route to synthesize an easily recycled photocatalyst using polyethylene terephthalate?PET?to disperse?g-C₃N₄?via electrospinning and subsequent hydrothermal treatment,obtaining T-g-C₃N₄/PET nanofibers.The design concept is to expose the g-C₃N₄ on the PET surface and convert it from inactivation to relive.Meanwhile,a series of analysis techniques such as FESEM,TEM,BET,FTIR,PL,DRS and 2D-XRD were employed to determine the morphology and composition of the resulted photocatalysts.In this study,sulfaquinoxaline?SQX?was chosen a model antibiotic.The performance of the T-g-C₃N₄/PET for degrading SQX was tested under solar irradiation.The results illustrates the T-g-C₃N₄/PET showed a high photocatalytic activity,and the activity was almost unaffected in a high background.It could be reused several times with no loss in performance in cycling photodegradation tests.Additionally,a possible pathway and mechanism for degrading sulfaquinoxaline with T-g-C₃N₄/PET were proposed,respectively,in which holes and·O₂^-were the predominant active species,and resulted in the oxidative degradation of antibiotics.In order to gain another load method,which is more manageable,green and can be applied other polymer nanofibers,in the previous work,we introduced a kind of porogen polyethylene glycol?PEG?.A solution containing g-C₃N₄,PEG and PET was electrospun,and followed by a post-processing to remove the PEG,obtainning a porous nanofibers?g-C₃N₄@PET?.Meanwhile,The obtained porous nanofibers?g-C₃N₄@PET?were characterized by various analysis technologies,which showed a uniformly porous structure with a high surface,significantly increasing a lot of active photocatalytic sites and the accessibility for substrates.Additionally,the porous nanofibers g-C₃N₄@PET exhibited a high photocatalytic performance and reusability.The photocatalytic mechanism was also researched by the addition of trapping agents and EPR tests,and accordingly,the probable mechanism was proposed.·O₂^-plays a main role in the antibiotics degradation.In summary,we hope the study can provide a new idea for designing the supported photocatalysts.