Font Size: a A A

Preparation And Antibacterial Of Rare-earth Doped TiO2

Posted on:2011-11-12Degree:MasterType:Thesis
Country:ChinaCandidate:F P WangFull Text:PDF
GTID:2121360308483332Subject:Biomedical engineering
Abstract/Summary:PDF Full Text Request
Nano titanium dioxide is applied to its early diagnosis and medical treatment by its nano properties; titanium dioxide is biological safety and good compatibility, it have been used for a wide range of improving tradition biomedical materials'compatibility; TiO2 also is a thorough and long-lasting antimicrobial bactericidal antibacterial materials and is widely used for improving the antibacterial properties of tradition biological materials and medical device surface and health care, TiO2 related to daily life goods conclude kitchen sanitation. household appliances. building materials. expressway facilities and so on.Titanium dioxide as a health-based antimicrobial material not only has antibacterial and clean air function, but also is non-toxic, tasteless, non-irritating, good heat resistance, chemical stability, low costs and so on, but it is undeniable that TiO2 has itsself problem, the most impotant is that the photocatalytic activity is not high.Metal ions doped can effectively improve the photocatalytic activity of TiO2. At present, scholars usually studied 1-3 species of rare earth doping titanium dioxide with one kind of method, but the rare earth doped titanium dioxide prepared in different ways, and they evaluated under different evaluation system results, so there is no comparative.At present, some scholars prepared 1-3 species of rare earth doped by using one method, or prepared rare earth doped titania by different methods, and evaluated under different evaluation system. There are some questions, their results cann't compared. So which rare earth element is the best for improving the photocatalytic activity of TiO2.This research work is mainly based on the preliminary study, using co-precipitation method and sol-gel method, prepared seven kinds of rare earth doped TiO2. and the Rhodamine B as a model organic compounds, compared all rare earth doped titanium dioxide properties. Including: evaluation of photocatalytic activity,measured adsorption capacity,and rare earth doped titania with higher activity were characterized by XRD, XPS, BET, SEM. Finally, rare earth doped titanium dioxide's antibacterial was identified by inhibitory.This paper studies'conclusions as following:1, The photocatalytic activity of rare earth doped titanium dioxide was prepared by coprecipitation method was significantly higher than was prepared by sol-gel method, the reasons maybe is: XRD patterns show that the rare earth doped titanium dioxide were prepared by two methods has a mixed crystal structure, but the content of anatase (have photocatalytic activity) prepared by coprecipitation is slightly higher than prepared by sol-gel method, like COP1.0wt% Gd-TiO2-800 and SG1 .0 wt% Gd-TiO2-600 have anatase is 80% and 70% respectively, the crystal size of rare earth doped titanium dioxide prepared by coprecipitation is much bigger than prepared by sol-gel method, 40.3nm and 26.9nm respectively;XPS analysis indicated that the surface of rare earth doped titania prepared by sol-gel method has C element, which come from precursor, it might be the main reason for decline in the photocatalytic activity;BET determination shown that the pores of rare earth doped titania was prepared by coprecipitation method are in the range of mesopores (2-50 nm), but those prepared by coprecipitation basically consist of 75% mesopores and 25% macropores (>50 nm). titania with macro/mesoporous are beneficial to the harvesting of light and reactants in or out, that maybe improve photocatalytic activity.SEM considered shown that the two samples consisted of more fine particles and agglomerates (2-20μm), but the particle morphology is very different. Most of the COP-Gd-TiO2 particles are spheroid,oblate spheroid,look looser, and some macropores could be observed on some particles:2. When evaluate all rare earth doped titanium dioxide, COP-Gd-TiO2 has highest catalytic activity in 14 kinds of materials (reaction rate constant for the 0.032min-1), the main reason may be that the gadolinium's 7f Electron shell of Gd is half-full state. When electron was capted by gadolinium ion, the half-filled e-form is destroyed, and decreased its stability, that need to transfer the electronic to oxygen molecules which adsorbed on the catalyst surface, consequently the gadolinium ion return to the original stable half-full electronic structure, in this this process electronics has been passed. Effectively inhibition of the electron-hole compound, improved the photocatalytic activity of titanium dioxide.3, The adsorption capacity of rare earth doped titanium dioxide prepared by sol-gel method is greater than same rare earth doped TiO2 prepared by precipitation, mainly due to the total surface area is larger (2.35 times) (SG1.0 wt.% Gd-TiO2-600: 36.9m2/g, COP1.0wt.% Gd-TiO2-800: 14.8 m2/g), but it can not determine its photocatalytic activity. 4, XPS analysis indicate that the atomic ratio of O/Ti is slightly larger than 2 on the surface of the catalysts (the average value is 2.02); the higher O content might be attributed to the presence of the Ln2O3 on the catalyst surface.5, The rare earth doped titanium dioxide has more obvious antibacterial properties, and the coprecipitation of rare earth doped titanium dioxide inhibition zone larger than sol-gel method, Gd, Yb, Sm-TiO2 have higher antimicrobial activity, this rerault is similar to the photocatalytic evaluation .
Keywords/Search Tags:the rare earth doped titanium dioxide, coprecipitation method, sol-gel method, Adsorption isotherm, antibacterial
PDF Full Text Request
Related items