Photocatalytic Bactericidal Of Er³⁺-Yb³⁺-Fe³⁺ Tri-doped TiO₂ Under Visible Light

By using rare earth ion Er³⁺,Yb³⁺ and transition metal Fe³⁺ co-doped, Er³⁺-Yb³⁺-Fe³⁺ tri-doped nano TiO₂ photocatalytic. Photolytic performance of tri-doped nano TiO₂ was tested. Specific tasks are as follows:1. Er³⁺-Yb³⁺-Fe³⁺ tri-doped nano TiO₂ photocatalytic power was prepared by the sol-gel.The photocatalytic was characterized by XRD,TEM,UV-Vis and 488nm Upconversion Photoluminescence.2. Irradiationed by visible light(150W), the effect of photocatalytic bactericidal on Escherichia coli(JM-109)by using 1050°Сcalcined tri-doped nano TiO₂ was studied. The process of photocatalytic bactericidal on concentration of photocatalytic, initial concentration of E.coli, illumination time, environment temperature and pH were researched. The upconversion and the energy absorption and transfer mechanism of photocatalytic sterilization process were proposed. At room temperature, bactericidal rate was 93.8% when the concentration of photocatalytic was 1.0mg/mL, initial concentration of Escherichia coli was3×107cfu/ml and the pH=7.4. By using Er³⁺-Yb³⁺-Fe³⁺ tri-doped nano TiO₂ powder and polyvinyl alcohol (PVA-1750), photocatalytic film was prepared. The relationship between bactericidal effect and the amount of PVA-1750 and photocatalytic was explorated preliminarily.3. Glass slides as carrier, added into polyethylene glycol (PEG), Er³⁺-Yb³⁺-Fe³⁺ tri-doped nano TiO₂ photocatalytic films were prepared by the sol-gel. The film was characterized by XRD and SEM.Calcination temperature, dosage of PEG and molecular of PEG were changed when the films were prepared and a series of antibacterial experiments were explorated accordingly. At room temperature, bactericidal rate was 78.6% when 2g PEG-2000 added and calcined at 400°С.4. At the same photocatalytic conditions and initial concentration of bacilli, suspension system, as reactants was mixed sufficiently, compared with constant system, bactericidal rate was greater. But films can be recycled and used again and the value of practical application was bigger.