Study On Preparation And Degradation Of Antibiotics By Graphene/Vanadium Bismuthate Composites

Objective In this study,a new photocatalyst with high photocatalytic activity,good stability,low cost and improved spectral response range of visible light was obtained by modifying bismuth vanadate.It has a certain practical significance for photocatalytic technology to provide more extensive application value in the treatment of dye wastewater and antibiotic pollutants.Methods Graphene oxide was prepared by the Hummers method.The photocatalyst of bismuth vanadate was prepared by hydrothermal method and the influence of preparation conditions on the performance of photocatalyst was investigated.By optimizing the experimental conditions,the bismuth vanadate sample with the best performance was obtained,and different amounts of graphene oxide,polypyrrole and bismuth vanadate samples were doped to realize the modification of bismuth vanadate.Modern instruments such as XRD,TEM,XPS,FT-IR and UV-vis.The prepared photocatalyst was subjected to series characterization,and its crystal structure,surface composition,surface structure and the like were analyzed.Rhodamine B and antibiotics were selected as simulated pollutants,and the prepared samples were subjected to photocatalytic performance experiments,reaction kinetics studies,photocatalytic degradation ultraviolet absorption spectroscopy and photocatalyst stability evaluation.Results Rhodamine B was used as a simulated pollutant to investigate the photocatalytic properties of the prepared samples.The prepared bismuth vanadate sample had the best degradation effect at pH=7,hydrothermal reaction temperature of 180°C and hydrothermal reaction time of 8 h.After 160 min of light,the degradation rate of BiVO₄ to rhodamine B was44.31%.The best performance of bismuth vanadate was combined with graphene oxide and polypyrrole.After 160 min of light,the degradation rate of rhodamine B was 94.25%in the binary composite with 3%graphene oxide?GO/BiVO₄?.The degradation rate of rhodamine B was reached 95.72%in the binary composite with 5%polypyrrole?PPy/BiVO₄?.Under the condition of light irradiation for 120 min,the degradation rate of rhodamine B reached 96.8%with 5%PPy/GO/BiVO₄ ternary composite photocatalyst.It shows that it has the best photocatalytic degradation performance.In addition,the degradation of Rhodamine B in each sample accords with the first-order reaction kinetics equation.And through the photocatalytic degradation recycling experiment,the new photocatalyst has better stability.At the same time,the ternary composite sample exhibited excellent photocatalytic degradation effects on tetracycline hydrochloride,chlortetracycline hydrochloride and oxytetracycline hydrochloride.Conclusions The photocatalytic activity of the modified barium vanadate material has been greatly improved.The doping of graphene oxide and polypyrrole has changed the reaction pathway of rhodamine B degradation of barium vanadate.Because graphene oxide has a large specific surface area,it increases the adsorption performance of the catalyst,which is beneficial to the separation of photogenerated electron-hole pairs,thereby improving the photocatalytic activity of the composite sample.Polypyrrole promotes electron transport and effectively promotes the separation of photogenerated carriers,thereby reducing the recombination probability of photogenerated electrons and holes,providing more surface reactive sites for photocatalytic reactions and further promoting the photocatalytic process.In addition,the new visible light catalyst has strong degradation effects on tetracycline hydrochloride,chlortetracycline hydrochloride and oxytetracycline hydrochloride.This research will make a great contribution to the development of new energy sources,improvement of the ecological environment,and promotion of human health.