载银TiO2薄膜制备及其光催化灭菌性能

在硫酸电解液中，用阳极氧化法在纯钛表面制备了纳米多孔TiO₂薄膜，并通过光沉积法进行了载银修饰。采用XRD、SEM对薄膜的形貌与相结构进行了表征，并考察了电流密度、电压和电解液浓度等对生成的TiO₂薄膜光催化灭菌性能的影响。结果表明：TiO₂薄膜由锐钛矿型和金红石型组成。随电压升高，金红石型的含量逐渐增多，微孔孔径增大，在电流密度为150 mA•cm^-2时，分别由120 V时的19%和93 nm增加到180 V时的96%和283 nm。电流密度的适当增大和适量的载银修饰有助于提高TiO₂薄膜光催化灭菌性能。在1 mol•L^-1硫酸溶液中，140 V/150 mA•cm^-2条件下制备的TiO₂薄膜，经3 g•L^-1硝酸银溶液中载银修饰后灭菌效果最佳。

Preparation and photocatalytic bactericidal activity of silver loaded TiO2 thin films

Photocatalytic nano-porous titanium dioxide films were prepared by the anodic oxidation method in sulfuric acid solution，and were loaded with silver by the photodeposition method.The microstructure and grain morphology in the films were characterized by SEM and XRD.The effect of anodizing parameters（anodizing voltage，current density and electrolyte concentration）on the photocatalytic bactericidal activity of TiO₂ films was investigated.It showed that the titanium oxide film was mainly composed of anatase and rutile TiO₂.With increasing anodizing voltage，the content of rutile TiO₂ increased，and the average diameters of nano-holes was enlarged.When the current density was 150 mA•cm^-2，the voltage increased from 120 V to 180 V，the content of rutile TiO₂ increased from 19% to 96%，the average diameters of nano-holes increased from 93 nm to 283 nm.A proper increase of current density and a suitable Ag loading could enhanced the photocatalytic activity of TiO₂ film.When prepared at 140 V/150 mA•cm^-2 in 1 mol•L^-1 sulfuric acid solution，and loaded with silver in 3 g•L^-1 silver nitrate solution，the Ag-TiO₂ film had the best photocatalytic bactericidal activity.The results suggested that photocatalytic bactericidal treatment with Ag-TiO₂ thin film has the potential for use as a new tool for water treatment.