Study On Antibacterial Properties Of La³⁺/Li⁺ Doped TiO₂ Nanomaterials

Titanium dioxide is widely used in coatings,plastics,paper,chemical fiber,rubber,cosmetics and other industries,but the application of TiO2 in ceramics is hindered,and the problems of low photocatalytic efficiency and poor antibacterial effect need to be solved.Li+ doped TiO2(Li+-TiO2)and La3+ doped TiO2(La3+-TiO2)nano-materials were prepared by sol-gel method and high energy ball milling process in this paper.The effects of ion doping amount,type of surfactant,calcination temperature,and calcination time on the antibacterial properties of TiO2 nano-materials prepared by sol-gel method were systematically studied.The effects of ion doping amount,milling time,and ball to powder weight ratio,on the antibacterial properties of TiO2 nano-powders prepared by high energy ball milling process were also systematically studied.The X-ray diffraction(XRD),Scanning electron microscope(SEM)and Fourier transform infrared spectroscopy(FT-IR)were used to analyse the chemical composition,phase composition,particle size and light absorption performance of the prepared nanometer materials.Under the conditions of visible light irradiation,the antibacterial properties of TiO2 nano-materials were investigated by flask oscillation method,and the best preparation process of antimicrobial iO2 nano-materials was determined.The XRD patterns indicate that the pure TiO2 is transformed from an amorphous state to anatase crystal form at 360? and the rutile TiO2 phase appears from the anatase crystal at 600?,while the transition temperature of doped TiO2 nano-materials increases to 700?.This indicates that doping ions can improve the crystal transformation temperature of TiO2 and the thermal stability of anatase.Doped TiO2 nano-materials can generate two phases or three phases after high energy ball milling with the increase of doping amount.The SEM micrographs show that the particles of doped TiO2 nano-materials prepared by the sol-gel method are homogeneous and compact,and the particle size increases with the temperature increasing.The particles of doped TiO2 nano-materials prepared by the high energy ball milling are uniform and dense,the size decreases with the increase of milling time,and the powder changes from local accumulation to well-distributed state with the ball milling time increasing.Under the best preparation process conditions,the antibacterial experiments show that the bactericidal rates of Li+-TiO2 and La3+-TiO2 nano-materials prepared by sol-gel method against E.coli and S.aureus are both above 91%,and the bactericidal rates of Li+TiO2 and La3+TiO2 nano-materials prepared by high energy ball milling against to E.coli and S.aureus are both above 85%.The bactericidal rates of the TiO2 nano-materials have been greatly increased compared to that of the pure TiO2 materials,which is only 35%.