Laser solid-phase synthesis of TiO anatase/rutile homojunctions for efficient photocatalytic hydrogen evolution.

Traditional methods for synthesizing TiO homojunctions are complex and challenging in controlling phase composition and junction quality. In this work, we have developed infrared laser solid-phase ablation of anatase TiO nanotubes to address these issues, systematically varying laser parameters to optimize the phase composition and junction quality. The synthesized homojunctions are characterized to understand their structure-activity relationship. The photocatalytic performance shows that the laser-ablated TiO nanostructures with an optimal anatase/rutile ratio of 1:3 exhibit the highest hydrogen production rate of 2388 µmol gh, doubling that of the pristine TiO nanotubes. This enhancement is attributed to the balanced presence of surface oxygen vacancies and Ti defects, accompanied with the effective spatial separation of electron-hole pairs induced by the anatase/rutile homojunctions. This study demonstrates a scalable and effective method for hydrogen production via solar energy conversion and expands the application field of pulsed laser synthesis technique.