What happens if anodic TiO2 nanotubes are soaked in H3PO4 at room temperature for a long time?

• Published in: Electrochemistry communications 2019-08, Vol.105, p.106501, Article 106501
• Main Authors: Wu, Lizhen, Li, Chen, Song, Ye, Zhang, Kun, Zhang, Jiajun, Li, Puying, Zhu, Xufei
• Format: Article
• Language: English
• Subjects: Dissolution-recrystallization; Flower-like structure; H3PO4 soaking; Supercapacitors; TiO2 nanotubes
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2019.106501

We have found that anodized amorphous TiO2 nanotubes can be transformed into rutile phase TiO2, resulting in the formation of a flower-like structure, when soaked in H3PO4 solution at room temperature for 2–4 days. The presence of PO43− ions in the soaking solution is believed to play a key role in the formation of the flower-like TiO2 structure. The resulting TiO2 flower-like material can be used as a binder-free electrode and exhibits obvious redox activity in AlCl3 solution and superior supercapacitive performance compared to conventional TiO2 nanotubes. The presented technique offers a simple, scalable, energy-saving, and cost-effective way to tailor the morphology and properties of anodized TiO2 nanotubes for different applications. [Display omitted] •Novel flower-like TiO2 structure is obtained by soaking TiO2 nanotubes in H3PO4 solution.•H3PO4-soaking of TiO2 nanotubes leads to “amorphous to rutile” phase transformation.•PO43− ions are believed to play a key role in the formation of flower-like structure.•H3PO4-soaking yields flower-like TiO2 with redox activity in AlCl3 solution.