Femtosecond Laser Induced Phase Transformation of TiO₂ with Exposed Reactive Facets for Improved Photoelectrochemistry Performance

Titanium dioxide (TiO₂) is one of the most promising candidates for photoelectrochemistry applications. For a high photoelectrochemistry performance, the control of crystal structure and crystal facet is essential. The phase transformation of TiO₂ is conventionally achieved by thermal annealing. Here, we report an approach for selective phase transformation of TiO₂ containing exposed reactive facets with improved photoelectrochemistry performance. After femtosecond laser processing, TiO₂ nanotubes with exposed reactive anatase {010} facets are prepared, and they have a maximum photocurrent density more than 5 times that of pure anatase. Additionally, this strategy can induce phase transformation in a selective area, which shows the advantages of patterning processing. Our method constructs a promising strategy for preparing functional nanomaterials with high performances and functionality.