Preparation And Application Of Semiconductor And Ferrite Nanocomposites

At present,China's water source organic pollution is very serious,There are more and more types of organic pollutants.Nitrophenols and antibiotics are considered to be the most common organic pollutants in wastewater from agriculture and industry,and it has the characteristics of high stability and difficult degradation.At the same time,domestic sewage contains more microorganisms,such as Escherichia coli?E.coli?and Staphylococcus aureus?S.aureus?,which are harmful to the human body.However,the treatment technology of these pollutant removal methods is still in the immature stage,and the cost is high,it is difficult to recycle,and there is a risk of secondary pollution.In particular,due to the excessive use of antibacterial drugs and irrational treatment,bacterial gene mutations and drug resistance gradually develop,resulting in more difficult sterilization.Therefore,it is particularly important to develop a catalyst material that is simple to prepare,cost-effective,and easy to recycle.In this paper,CuS/Eggshell and CuSe/Eggshell nanocomposite materials with near-infrared?NIR?light absorption and conversion effects were prepared using an economical and simple method based on waste eggshells as templates.The MgFe₂O₄/Eggshell nanocomposite with magnetic properties was prepared by calcination.The photocatalytic activity,antibacterial performance,and working mechanism were studied.The main research work of this paper is as follows:?1?CuS nanorods with a diameter of about 30 nm and a length of about 100 nm were synthesized by the co-precipitation method.CuS/Eggshell nanocomposites with CuS nanorods supported on the surface of egg shell powder were prepared.The degradation rate of 4-NP by CuS/Eggshell nanocomposite can reach 97%within 35minutes,and has good antibacterial effect.Under the irradiation of NIR light,nanomaterials undergo efficient energy transfer,resulting in the generation of a large number of free radicals?·OH and·CO₃^-?,which greatly improves the performance of nanocomposites.Through photocatalysis,photothermal and photodynamic synergistic mechanism,organic pollutants are effectively degraded and pathogenic bacteria are ablated.?2?CuSe nanospheres with a particle size of about 50 nm were synthesized by the co-precipitation method.CuSe/Eggshell nanocomposites with CuSe nanospheres supported on the surface of eggshell powder were prepared.Under the condition of no light,the degradation rate of 4-NP by CuSe/Eggshell nanocomposites can reach 96%in 15min.But under NIR light irradiation,it can effectively and stably catalyze the degradation of 98%4-NP in 6 minutes,which is 3 times higher than without near-infrared light irradiation.At the same time,a large number of free radicals?·OH and·CO₃^-?were detected to participate in the degradation of 4-NP.In addition,CuSe/Eggshell nanocomposites have good antibacterial properties.?3?MgFe₂O₄ nanoparticles with a particle size of about 5 nm were synthesized by the calcination method,and the MgFe₂O₄/Eggshell nanocomposite supported on the surface of the eggshell powder was prepared at a calcination temperature of700°C.Under visible light irradiation,the degradation rate of TC of MgFe₂O₄/Eggshell nanocomposites can reach 90%in 60min.By changing the condition variables of photocatalytic degradation of TC,the optimal conditions of photocatalytic degradation of TC were further explored.