Laboratoire de Photovoltaïque, Centre de Recherches et des Technologies de l'Energie, Technopole de Borj-Cédria, BP 95, 2050 Hammam-Lif, Tunisia.
Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35000 Rennes, France.
Colloids Surf B Biointerfaces. 2018 Oct 1;170:92-98. doi: 10.1016/j.colsurfb.2018.06.005. Epub 2018 Jun 5.
This study investigates the effect of the diameter of TiO nanotubes and silver decorated nanotubes on optical properties and photocatalytic inactivation of Escherichia coli under visible light. The TiO nanotubes (TiO-NTs) were prepared using the electrochemical method varying the anodization potential starting from 20 V until 70 V. The Ag nanoparticles were carried out using the photoreduction process under the same experimental conditions. The diameter size was determined using the scanning electronic microscopy (SEM). TiO-NTs diameter reached ∼100 nm at 70 V. Transmission electronic microscopy (TEM) imaging confirmed the TiO-NTs surface decoration by silver nanoparticles. The Ag-NPs average size was found to be equal to 8 nm. The X-Ray diffraction (XRD) analysis confirm that all TiO-NTs crystallize in the anatase phases regardless the used anodization potential. The decrease of the photoluminescence (PL) intensity of Ag NPs decorated TiO-NTs indicates the decrease of the specific area when the nanotubes diameter increases. The UV-vis absorbance show that the absorption edges was bleu shifted with the increasing of nanotubes diameter, which can be explained by the increase of the crystallites average size. The bacterial adhesion and inactivation tests were carried in the dark and under light. Bacteria were seen to adhere on TiO-NTs in the dark; however, under light the bacteria were killed before they establish a strong contact with the TiO-NTs and Ag/TiO-NTs surfaces. Bacterial inactivation kinetics were faster when the anodizing potential of the NTs-preparation increases. A total bacterial inactivation was obtained on ∼100 nm nanotubes diameter within 90 min. This result was attributed to the enhancement of the TNTs crystallinity leading to reduced surface defects. Redox catalysis was seen to occur under light on the TiO-NTs and Ag/TiO-NTs. the photo-induced antibacterial activity on the AgO/AgO decorated TiO-NTs was attributed to the interfacial charge transfer mechanism (IFCT).
本研究考察了 TiO 纳米管的直径和银修饰纳米管对大肠杆菌在可见光下的光学性质和光催化失活动力学的影响。TiO 纳米管（TiO-NTs）通过电化学方法制备，从 20V 开始改变阳极化电位，直至 70V。Ag 纳米颗粒通过相同的实验条件下的光还原过程进行。使用扫描电子显微镜（SEM）确定直径尺寸。在 70V 时，TiO-NTs 的直径达到约 100nm。透射电子显微镜（TEM）成像证实了 TiO-NTs 表面被银纳米颗粒修饰。Ag-NPs 的平均尺寸为 8nm。X 射线衍射（XRD）分析证实所有 TiO-NTs 无论使用的阳极化电位如何，均结晶为锐钛矿相。Ag NPs 修饰的 TiO-NTs 的光致发光（PL）强度的降低表明，当纳米管直径增加时，比表面积减小。紫外-可见吸收光谱表明，吸收边缘随着纳米管直径的增加而蓝移，这可以解释为晶粒度平均尺寸的增加。在黑暗中和光照下进行细菌粘附和失活动力学测试。在黑暗中观察到细菌在 TiO-NTs 上粘附；然而，在光照下，细菌在与 TiO-NTs 和 Ag/TiO-NTs 表面建立牢固接触之前就被杀死。随着 NTs 制备的阳极化电位增加，细菌失活动力学更快。在 90 分钟内，约 100nm 纳米管直径的总细菌失活。这一结果归因于 TNTs 结晶度的提高，从而减少了表面缺陷。在光照下，TiO-NTs 和 Ag/TiO-NTs 上发生了氧化还原催化作用。AgO/AgO 修饰的 TiO-NTs 上的光诱导抗菌活性归因于界面电荷转移机制（IFCT）。
