Lithium ion-inserted TiO2 nanotube array photoelectrocatalysts

- Li+ is quickly inserted into TiO2 nanotube arrays (TNTs) by electrochemical methods.
- Li+ insertion enhances photocurrent generation and IPCE by ∼70% and 250%, respectively.
- Photoelectrocatalytic performance is enhanced by 2.5 times with Li+ insertion for 3 s.
- Li+ prevents charge recombination, enhancing the generation of e− and OH.