In recent years, photocatalytic reactions on anodic TiO₂ nanotubes have been intensively investigated. In order to show photocatalytic activity, anodically formed nanotubes need to be crystallized to anatase. This is conventionally done by thermal annealing in air at temperatures 400–600 °C. Recently, a so‐called “water annealing” treatment has been reported to be effective to also create a highly active form for photocatalysis. Here we report on the feasibility of using a water annealing treatment of TiO₂ nanotubes to create a photocatalyst for H₂ production that is as active as conventional thermal annealing. If the water‐annealed samples are additionally hydrogenated to a so‐called “grey” modification, a further significant improvement of the photocatalytic activity for H₂ evolution can be achieved – this without the use of any noble metal co‐catalyst. A combination of water annealing, thermal annealing, followed by hydrogenation can deliver a H₂ generation activity that is more than five times higher than that achieved by thermal annealing of anodic TiO₂ nanotubes.

中文翻译：

---

具有白色和灰色修饰的水封TiO2纳米管产生光催化氢

近年来，对阳极TiO ₂纳米管的光催化反应进行了深入研究。为了显示光催化活性，需要将阳极形成的纳米管结晶为锐钛矿。通常，这是通过在空气中于400-600°C的温度下进行热退火来完成的。近来，据报道所谓的“水退火”处理对于产生光催化的高活性形式也是有效的。在这里，我们报告了使用TiO ₂纳米管的水退火处理来创建H ₂的光催化剂的可行性。与传统的热退火一样活跃。如果将水退火的样品另外加氢至所谓的“灰色”修饰，则可以进一步显着改善H ₂析出的光催化活性，而无需使用任何贵金属助催化剂。水退火，热退火以及随后的氢化的组合可以产生比通过阳极TiO ₂纳米管的热退火获得的高出五倍的H ₂产生活性。