Preparation Of Carbon Nitride-based Supported Composite Photocatalyst And Study On Degradation Of Ciprofloxacin

In recent years,with the rapid development of antibiotics in the pharmaceutical and medical industries,they are widely present in the water environment.The increasingly serious antibiotic pollution in the water environment has seriously threatened the health of humans and ecosystems and has attracted widespread public attention.Ciprofloxacin(Ciprofloxacin,CIP)is one of the most representative quinolone antibiotics.Traditional techniques cannot effectively remove residual ciprofloxacin in wastewater.Photocatalytic oxidation is used in the treatment of ciprofloxacin wastewater due to its green.The characteristics of environmental protection and high efficiency have attracted the attention of scientists in recent years.Among them,graphite-like carbon nitride(g-C₃N₄)is due to its low cost,good visible light response and suitable band gap with unique optical and electronic properties.(2.7eV)has received extensive attention from researchers,but the single graphite-like carbon nitride photocatalyst has defects such as low light absorption,difficult recovery,and poor treatment effect.It is very important to find an efficient method to treat ciprofloxacin in the water environment.Therefore,based on the above problems,this study uses carbon fiber cloth(Carbon Fiber Cloth,CFC)as the catalyst carrier to prepare a high-efficiency heterojunction supported photocatalyst(MoS₂/B-g-C₃N₄/CFC)to remove the typical antibiotic ciprofloxacin in water.The control of antibiotics organic pollution in water has important theoretical significance and practical value.(1)This research aims to increase the utilization rate of photocatalyst,promote electron-hole transfer,and solve the problem of low efficiency of traditional photocatalytic treatment of organic pollutants in water.This study prepares B-g-C₃N₄and B-g-C₃N₄/CFC through solvothermal-thermal polymerization method.When water temperature is 22?,and use 30 W white LED light,the optimal process parameters of photocatalytic degradation system are as follows:the most suitable catalyst loading is40%,and wastewater pH value is 7,and the composite photocatalyst,the best effective depth is 0.5 cm.When the initial concentration of the pollutant ciprofloxacin is 10mg/L ciprofloxacin,after 3h photocatalytic degradation of B-g-C₃N₄ and B-g-C₃N₄/CFC,the degradation rates are 80.2%and 87.5%,respectively;Both catalysts can maintain excellent stability after multiple cycles of use.The degradation mechanism and degradation kinetics of g-C₃N₄ are discuss in depth.(2)In this study,flower spherical MoS₂ is prepare by one-step hydrothermal method,and MoS₂/B-g-C₃N₄/CFC is successfully prepare by loading MoS₂ onto B-g-C₃N₄/CFC by ultrasonic precipitation method.It improve the separation of photoelectric charge and the utilization of visible light.When the water temperature is22?and a 30W positive white LED lamp is used as the visible light source,the optimal process parameters of the photocatalytic degradation system are the most suitable MoS₂loading of 0.2 g,the optimal pH value of 7,and heterojunction The best effective depth of the supported photocatalyst is 0.5cm.When the initial concentration of the pollutant ciprofloxacin is 10mg/L,the degradation rate is 98.2%after 3h of photocatalytic degradation.After five CIP cycle stability tests,the heterojunction supports photocatalyst still has excellent stability in use.The research results show that the composite photocatalytic system effectively improves the photocatalytic effect of ciprofloxacin.On this basis,the degradation mechanism and degradation kinetics of the composite photocatalyst MoS₂/B-g-C₃N₄/CFC are discussed.