原位还原法制备介孔Ag-TiO_2抗菌剂及其性能研究

In-situ reduction preparation and properties of mesoporous Ag-TiO_2 antibacterial agent

以TiO2介孔球为载体,采用原位化学还原法制备了介孔Ag-TiO2抗菌剂。重点研究了不同载银量下Ag-TiO2抗菌剂的吸附性能、光催化性能及抗菌性能,对相关机理进行了探讨,并初步将样品应用于光催化抗菌涂层制备。研究结果表明:负载的Ag以金属单质形式存在,纳米Ag的沉积会在一定程度上堵塞TiO2球介孔结构,当Ag理论负载量(质量百分比)大于5%时,Ag-TiO2抗菌剂的吸附能力大幅降低。所形成的纳米Ag通过与TiO2形成肖特基结,可抑制光生电子、空穴复合,提高TiO2光催化活性;同时纳米Ag还可通过与液相中溶解氧的反应释放出Ag+离子,表现出抗菌活性,当Ag理论负载量为2.5%时,样品具有最优的光催化和抗菌综合性能,展现出在光催化抗菌涂层方面的应用潜力。

Mesoporous Ag-TiO2 antibacterial agent was prepared via in-situ reduction method,using TiO2 mesoporous microspheres as support.Adsorption properties,photocatalytic activities and antibacterial performance of various Ag-TiO2 antibacterial agents with different silver loading were mainly studied,and the related mechanisms were also discussed,then the Ag-TiO2 antibacterial agent was initially used to prepare antibacterial film.The results show that the loaded Ag exists in the form of elemental silver,and the precipitation of Ag nanoparticles will block the mesopores of TiO2 microspheres,so when the theoretical loading amount of Ag is over 5％,the adsorption ability decreased seriously.The combination of photo-generated electrons and holes can be inhibited because of the schottky junction formed between Ag and TiO2,thus increasing the photocatalytic activities.Meanwhile,Ag＋ ions can release from Ag nanoparticles via oxidization by dissolved oxygen,inducing antibacterial activities.When the theoretical loading amount of Ag is 2.5％,the comprehensive properties of the Ag-TiO2 antibacterial agent reach the best.Moreover,such antibacterial agent also shows its great potential application in the preparation of antibacterial coatings.