Synthesis Of Ce-doped Boron Nitride Based Nano-composites For The Adsorption Of Antibiotics

In recent years,with the development of pharmaceutical technology and health,the output and consumption of antibiotics have increased around the world.A large number of antibiotics that fail to be effectively treated have flowed into rivers,soil,lakes,and other environments.At present,there have been a number of reports that different degrees of antibiotic contamination can be detected in many watersheds around the world,and increasingly serious drug resistance of microorganisms has developed rapidly.A large amount of antibiotics in the natural ecosystem has seriously threatened the balance of ecosystems and human health,and become an issue of public health.Among the methods that have already been proposed,the adsorption method is considered to be one of the most application prospects because of its advantages of low energy cost,fast adsorption speed,high efficiency,safety,etc.In this work,the physical and chemical properties of BN based materials were improved to improve their adsorption properties by means of metal and hetero-element doping,pore-making and spatial structure modification.The structural composition and properties of the synthetic adsorbents were analyzed by SEM,TEM,FT-IR,XRD,N₂ adsorption-desorption,XPS,and UV-vis DRS.The adsorption performance was studied by changing adsorption conditions,and the mechanism was discussed in combination with adsorption kinetics models,isotherm models,and thermodynamic analysis.The study further expanded the application of boron nanomaterials in the field of adsorption and provides the data of basic research for BN materials in environmental governance.1.The formation of pores and the doping of the Ce were achieved together through the in-situ calcination,and the Ce doped boron nitride nanosheets（p-Ce-BNNS）was synthesized.It successfully promoted the specific surface area and pore volume,which increased the removal efficiency of BN for TC from 63.4%to 91.3%,and the equilibrium adsorption capacity could reach 242 mg/g.The adsorption process conformed to the pseudo-second-order kinetic model and Freundlich isotherm model,indicating that chemical interaction played an important role in the adsorption process.p-Ce-BNNS has good chemical stability and recycling performance.After 10 cycles,the removal rate of TC decreased from 99.59%to 93.01%,only 6.58 percentage points lower,which made p-Ce-BNNS more potential for practical application.2.Ce₂O₂S doped boron-carbon-nitrogen nanotubes（Ce-BCNNT）were successfully synthesized by one-step calcination using surfactant（P123）with long carbon chains as a template and source of C.The addition of C made the original lamellar structure of BN easy to bend and fold.Under the control of synthesis temperature,the thin lamellar structure could be crimped into tubular structure in coordination with the doping of Ce₂O₂S.The molding degree increased with the rise of calcination temperature.The maximum adsorption capacity of Ce-BCNNT calculated by the Langmuir model was 294.1 mg/g.The chemical interaction played an important role in the adsorption process which conformed to the pseudo-second-order kinetic model.Isotherm studies showed that the adsorption mechanism changes with the change of the relative amount of Ce-BCNNT and TC.Adsorption was a spontaneous and exothermic process.The high chemical stability of Ce-BCNNT enabled it to adsorb TC efficiently in wide temperature（20～50℃）and p H range（3～11）and ion coexisting environment.The excellent recycling performance of Ce-BCNNT made it a promising application for antibiotic adsorption in complex and harsh environments.