Laser solid-phase synthesis of TiO ₂ anatase/rutile homojunctions for efficient photocatalytic hydrogen evolution

Abstract

Traditional methods for synthesizing TiO 2 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 2 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 2 nanostructures with an optimal anatase/rutile ratio of 1:3 exhibit the highest hydrogen production rate of 2388 µmol g −1 h −1 , doubling that of the pristine TiO 2 nanotubes. This enhancement is attributed to the balanced presence of surface oxygen vacancies and Ti 3+ 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.