Pablos Cristina, Marugán Javier, van Grieken Rafael, Dunlop Patrick Stuart Morris, Hamilton Jeremy William John, Dionysiou Dionysios D, Byrne John Anthony
Department of Chemical and Environmental Technology, ESCET, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, Madrid, Spain.
Nanotechnology and Integrated BioEngineering Centre (NIBEC), Ulster University, Newtownabbey BT37 0QB, Northern Ireland, UK.
Molecules. 2017 Apr 28;22(5):704. doi: 10.3390/molecules22050704.
TiO₂ photocatalysis is considered as an alternative to conventional disinfection processes for the inactivation of waterborne microorganisms. The efficiency of photocatalysis is limited by charge carrier recombination rates. When the photocatalyst is immobilized on an electrically conducting support, one may assist charge separation by the application of an external electrical bias. The aim of this work was to study electrochemically assisted photocatalysis with nitrogen doped titania photoanodes under visible and UV-visible irradiation for the inactivation of . Aligned TiO₂ nanotubes were synthesized (TiO₂-NT) by anodizing Ti foil. Nanoparticulate titania films were made on Ti foil by electrophoretic coating (P25 TiO₂). N-doped titania nanotubes and N,F co-doped titania films were also prepared with the aim of extending the active spectrum into the visible. Electrochemically assisted photocatalysis gave higher disinfection efficiency in comparison to photocatalysis (electrode at open circuit) for all materials tested. It is proposed that electrostatic attraction of negatively charged bacteria to the positively biased photoanodes leads to the enhancement observed. The N-doped TiO₂ nanotube electrode gave the most efficient electrochemically assisted photocatalytic inactivation of bacteria under UV-Vis irradiation but no inactivation of bacteria was observed under visible only irradiation. The visible light photocurrent was only a fraction (2%) of the UV response.
二氧化钛光催化被认为是用于灭活水中微生物的传统消毒工艺的一种替代方法。光催化效率受电荷载流子复合率的限制。当光催化剂固定在导电载体上时，可以通过施加外部电偏压来辅助电荷分离。这项工作的目的是研究在可见光和紫外-可见光照射下，用氮掺杂二氧化钛光阳极进行电化学辅助光催化对（此处原文缺失具体对象）的灭活作用。通过对钛箔进行阳极氧化合成了排列整齐的二氧化钛纳米管（TiO₂-NT）。通过电泳涂覆在钛箔上制备了纳米颗粒二氧化钛薄膜（P25 TiO₂）。还制备了氮掺杂二氧化钛纳米管和氮、氟共掺杂二氧化钛薄膜，目的是将活性光谱扩展到可见光范围。与光催化（开路电极）相比，电化学辅助光催化对所有测试材料都具有更高的消毒效率。有人提出，带负电荷的细菌对带正电偏压的光阳极的静电吸引导致了所观察到的效率提高。氮掺杂二氧化钛纳米管电极在紫外-可见光照射下对细菌的电化学辅助光催化灭活效率最高，但在仅可见光照射下未观察到细菌灭活。可见光光电流仅为紫外响应的一小部分（2%）。
