In this paper we prepare facetted “black” TiO₂ nanotube arrays (NTAs) with a bamboo‐type structure which exhibits an enhanced performance for open‐circuit H₂ generation without the use of any noble metal co‐catalyst. The TiO₂ nanotubes were formed by applying alternating positive and negative voltages. During the electrochemical formation, not only a bamboo structure is formed but the tubes are reduced in the cathodic cycle. After a rapid annealing treatment of these tubes in air at 500 °C for 10 s, the bamboo rings (knots) provide (001) facets preferentially located at the knot, while (101) planes prevail on the smooth part of tube between knots, as shown by TEM. The short annealing time keeps Ti³⁺/oxygen vacancies (V_O) as co‐catalytically active centers still preserved in the TiO₂ NTAs. The results of intensity modulated photocurrent spectroscopy (IMPS) and open‐circuit potential decay measurements (V_OC) indicate that these faceted and reduced TiO₂ nanotube arrays provide an efficient separation and reaction of photo‐generated charge carriers, leading to an improved photocatalytic H₂ evolution performance.

中文翻译：

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电化学刻面竹型TiO2纳米管可增强开路氢气释放

在本文中，我们制备了具有竹型结构的多面“黑色” TiO ₂纳米管阵列（NTA），该结构在不使用任何贵金属助催化剂的情况下，对开路H ₂生成表现出增强的性能。通过施加交替的正负电压来形成TiO ₂纳米管。在电化学形成过程中，不仅形成了竹结构，而且在阴极循环中管子也减少了。在500°C的空气中对这些管子进行快速退火处理10 s后，竹环（结）提供了优先位于结子的（001）个小平面，而结子之间的管子的光滑部分占优势（101）个平面，如TEM所示。较短的退火时间可保持Ti ³⁺ /氧空位（V _O）作为共催化活性中心仍保留在TiO ₂ NTA中。强度调制光电流能谱（IMPS）和开路电势衰减测量（V _OC）的结果表明，这些多面且还原的TiO ₂纳米管阵列可有效分离和反应光生电荷载流子，从而改善了H的光催化性能。₂进化性能。