Preparation Of Cerium Based Photocatalytic Materials And Their Photocatalytic,Degradation,and Antibacterial Properties

In recent years,the excessive use of antibiotics has led to increasingly serious water pollution problems.At the same time,a large amount of antibiotics exist in water,inducing the production of bacterial resistance genes.This seriously affects the aquatic ecological balance and human health.Therefore,it is particularly important to develop research on water treatment technologies that can degrade antibiotics and have antibacterial properties.CeO₂,due to its low price,safety,non-toxicity,and excellent photocatalytic performance,has become a research hotspot in the field of photocatalytic materials.Based on CeO₂ nanomaterials,this article constructs a series of CeO₂/Ag,CeO₂/g-C₃N₄,and CeO₂/g-C₃N₄/Ag nanophotocatalytic materials with good photoresponsive effects.Using SEM,XRD,FT-IR,UV-DRS,XPS,BET,PL and other testing methods,the photocatalytic materials are characterized and analyzed,and the photocatalytic degradation and antibacterial properties of CeO₂/Ag,CeO₂/g-C₃N₄,and CeO₂/g-C₃N₄/Ag are studied.The main research findings are as follows:（1）CeO₂ was prepared by hydrothermal method using cerium nitrate,potassium bromate and asparagine as raw materials.A composite of CeO₂ and different masses of Ag NO₃ was obtained by reduction-deposition method.The photocatalytic degradation of tetracycline（TC）and antibacterial effects of the composite material were investigated.Among them,CeO₂/Ag-0.1 showed good photocatalytic degradation performance for TC.Under the conditions of 90 min illumination,addition amount of 0.8 g/L and p H=6,the degradation efficiency for TC at an initial concentration of 30 mg/L reached 96.4%,and the reusability was better.The photocatalytic antibacterial effect of CeO₂/Ag-0.1 on B.subtilis,E.coli and S.aureus was studied,and the results showed that the antibacterial efficiency against the three bacteria after 90 min of illumination was 100%,100%and92.5%,respectively.The degradation mechanism and antibacterial mechanism of CeO₂/Ag for TC were also studied.（2）CeO₂/g-C₃N₄ composite material was prepared by hydrothermal method using cerium nitrate,potassium bromate,asparagine and melamine as raw materials.The photocatalytic degradation of tetracycline（TC）and antibacterial effects of CeO₂/g-C₃N₄nanocomposites with different amounts of g-C₃N₄ were explored.Among them,CeO₂/g-C₃N₄-0.25 showed good photocatalytic degradation performance for TC.Under the conditions of 90 min illumination,addition amount of 0.8 g/L and p H=6,the degradation efficiency for TC at an initial concentration of 50 mg/L reached 97.2%,and the reusability was better.The photocatalytic antibacterial effect of CeO₂/g-C₃N₄-0.25 on B.subtilis,E.coli and S.aureus was studied,and the results showed that the antibacterial efficiency against the three bacteria after 90 min of illumination was 92%,94%and 86%,respectively.The degradation mechanism and antibacterial mechanism of CeO₂/g-C₃N₄for TC were also studied.（3）Ag was combined with CeO₂/g-C₃N₄-0.25 by reduction-deposition method to prepare CeO₂/g-C₃N₄/Ag composite materials with different ratios according to the different amounts of Ag.Among them,CeO₂/g-C₃N₄/Ag-0.1 showed good photocatalytic degradation performance for TC.Under the conditions of 90 min illumination,addition amount of 0.8 g/L and p H=6,the degradation efficiency for TC at an initial concentration of 55 mg/L reached 97.9%,and the reusability was better.The photocatalytic antibacterial effect of CeO₂/g-C₃N₄/Ag-0.1 on B.subtilis,E.coli and S.aureus was studied,and the results showed that the antibacterial efficiency against the three bacteria after 90 min of illumination was 100%,96%and 92%,respectively.The degradation mechanism and antibacterial mechanism of CeO₂/g-C₃N₄/Ag for TC were also studied.