Anodic TiO2 nanotubes: Influence of top morphology on their photocatalytic performance

The present work investigates the photocatalytic performance of TiO2 nanotubes with different tube top morphologies. Such morphological variations are obtained when growing self-organized nanotube arrays under different (but widely used) anodization conditions. We compare the most typical appearances of tube tops that are: i) “grassy” tubes, ii) tubes with initiation layers, iii) doubled anodized and iv) “open” tubes. The results show that tubes with an open, defined mouth have a significantly enhanced photocatalytic performance in open circuit, dye degradation experiments as well as when used as a photoanodes for photoelectrochemical water splitting.

► Self-organized TiO2 nanotube arrays can be grown to different morphologies.
► Open mouth tubes have a significantly enhanced photocatalytic performance.
► This is beneficial for photodegradation or photoelectrochemical water splitting.