Ultra-thin dark amorphous TiOx hollow nanotubes for full spectrum solar energy harvesting and conversion‡

Dark titania (TiOx) have been widely used for solar energy harvesting and conversion applications due to its excellent light absorbing performance throughout the ultraviolet near infrared wavelength band, low cost, non-toxic nature. However, synthesis methods of dark TiOx are usually complicated time-consuming. Here we report a facile rapid method fabricate amorphous (am-TiOx) hollow nanotube arrays on nanoporous anodic alumina oxide (AAO) templates using atomic layer deposition. Systematic investigation was performed demonstrate that Ti3+ O- species in am-TiOx ultra-thin films, as well spatial distribution these films vertical side walls AAO two major mechanisms black color. Importantly, film deposition took ~18 min only produce optimized ~4‐nm‐thick film. Representative were demonstrated photocatalytic reduction silver nitrate photothermal vapor generation, revealing potential am-TiOx/AAO structures full spectrum conversion.