| The extensive use of antibiotics has led to the long-term presence of antibiotics in environmental waters.It is persistent pollutant which caused serious harm to the ecological environment.Photocatalytic oxidation technology has been regarded as the promising method for antibiotics wastewater treatment due to cheapness,high photocatalytic activity,no secondary pollution and mild reaction conditions.Ti O2/graphene powder hasbeen widelystudiedinrecentyearsbecauseofitsexcellent photocatalytic activity.Although Ti O2/graphene films possess a series of advantages,such as easy separating,stable property and so on,it is limited by some factors,such as low quantum and poor photocatalytic efficiency.The issue can be solved by introducing template to prepare mesoporous films.Therefore,mesoporous Ti O 2/reduced graphene oxide?Ti O 2/r GO?mu lt ila yer fi lm s were prepa red by sol-gel proce ss ing and dip-coati ng technique using polyvinylpyrrolidone?PVP?or the triblock copolymer PEO20PPO70PEO20?P123?as template.The mesoporous Ti O2/r GO films were characterized and analyzed by X-ray diffraction?XRD?,scanning electron microscopy?SEM?,Brunauer-Emmett-Teller?BET?,UV-visible diffusereflectancespectroscope?UV-vis?,Ramanspectroscopy,photoluminescence?PL?spectroscopytechnology.Thephotocatalytic properties and cyclic stability of the mesoporous Ti O2/r GO films were investigated by the method of oxytetracycline photodegradation and a comparison between P123 template and PVP template was conducted.The main results were summarized as follows:1.r GO layers could increase the dispersion of Ti O2,expand the photocatalyst response range to visible light and inhibit the recombination ofphotogeneratedelectron-holepairs,therefore,thephotocatalytic efficiency of mesoporous Ti O2/r GO films was enhanced.2.The template could further distribute Ti O2 nanoparticles and refine the crystal grains.Compared with Ti O2/r GO films,the mesoporous Ti O2/r GO films could improve specific surface area,main pore size and lifetime of photocarrier.As template,P123 was better than PVP.3.Compared with Ti O2/r GO films,mesoporous Ti O2/r GO films showed high photocatalytic degradation efficiency of oxytetracycline under UV light and sunlight.The Ti O2?10wt%PVP?/r GO films and Ti O2?5wt%-P123?/r GO films revealed the best photocatalytic activity.Degradation efficiencyofoxytetracyclineforTi O2?10wt%PVP?/r GOfilmsand Ti O2?5wt%P123?/r GO films exceeded 90.30%and 90.91%at 135min under UV light,moreover,exceeded 90.61%and 91.52%at 50min under sunlight,respectively.After repeatedly recovery test,Ti O2?10wt%PVP?/r GO films andTi O2?5wt%P123?/r GOfilmsstillretainedhighphotocatalytic degradation efficiency,and it is enormous for the industry application potentiality. |
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